Useful or not, from you.
react-native react native 0.62 crash down in android 4.4.2

step1 npx react-native init test2 step2 npx react-native run-android, test2 app cannot run in android4.4.2 step3 open android in android studio, run,get message:

1723-1723/com.test2 E/AndroidRuntime: FATAL EXCEPTION: main
    Process: com.test2, PID: 1723
    java.lang.RuntimeException: Unable to create application com.test2.MainApplication: java.lang.RuntimeException: Requested enabled DevSupportManager, but DevSupportManagerImpl class was not found or could not be created
        at android.app.ActivityThread.handleBindApplication(ActivityThread.java:4617)
        at android.app.ActivityThread.access$1800(ActivityThread.java:139)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1316)
        at android.os.Handler.dispatchMessage(Handler.java:102)
        at android.os.Looper.loop(Looper.java:136)
        at android.app.ActivityThread.main(ActivityThread.java:5315)
        at java.lang.reflect.Method.invokeNative(Native Method)
        at java.lang.reflect.Method.invoke(Method.java:515)
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:864)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:680)
        at dalvik.system.NativeStart.main(Native Method)
     Caused by: java.lang.RuntimeException: Requested enabled DevSupportManager, but DevSupportManagerImpl class was not found or could not be created
        at com.facebook.react.devsupport.DevSupportManagerFactory.create(DevSupportManagerFactory.java:90)
        at com.facebook.react.ReactInstanceManager.<init>(ReactInstanceManager.java:238)
        at com.facebook.react.ReactInstanceManagerBuilder.build(ReactInstanceManagerBuilder.java:281)
        at com.facebook.react.ReactNativeHost.createReactInstanceManager(ReactNativeHost.java:87)
        at com.facebook.react.ReactNativeHost.getReactInstanceManager(ReactNativeHost.java:39)
        at com.test2.MainApplication.onCreate(MainApplication.java:47)
        at android.app.Instrumentation.callApplicationOnCreate(Instrumentation.java:1009)
        at android.app.ActivityThread.handleBindApplication(ActivityThread.java:4614)
        at android.app.ActivityThread.access$1800(ActivityThread.java:139) 
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1316) 
        at android.os.Handler.dispatchMessage(Handler.java:102) 
        at android.os.Looper.loop(Looper.java:136) 
        at android.app.ActivityThread.main(ActivityThread.java:5315) 
        at java.lang.reflect.Method.invokeNative(Native Method) 
        at java.lang.reflect.Method.invoke(Method.java:515) 
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:864) 
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:680) 
        at dalvik.system.NativeStart.main(Native Method) 
     Caused by: java.lang.reflect.InvocationTargetException
        at java.lang.reflect.Constructor.constructNative(Native Method)
        at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
        at com.facebook.react.devsupport.DevSupportManagerFactory.create(DevSupportManagerFactory.java:80)
        at com.facebook.react.ReactInstanceManager.<init>(ReactInstanceManager.java:238) 
        at com.facebook.react.ReactInstanceManagerBuilder.build(ReactInstanceManagerBuilder.java:281) 
        at com.facebook.react.ReactNativeHost.createReactInstanceManager(ReactNativeHost.java:87) 
        at com.facebook.react.ReactNativeHost.getReactInstanceManager(ReactNativeHost.java:39) 
        at com.test2.MainApplication.onCreate(MainApplication.java:47) 
        at android.app.Instrumentation.callApplicationOnCreate(Instrumentation.java:1009) 
        at android.app.ActivityThread.handleBindApplication(ActivityThread.java:4614) 
        at android.app.ActivityThread.access$1800(ActivityThread.java:139) 
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1316) 
        at android.os.Handler.dispatchMessage(Handler.java:102) 
        at android.os.Looper.loop(Looper.java:136) 
        at android.app.ActivityThread.main(ActivityThread.java:5315) 
        at java.lang.reflect.Method.invokeNative(Native Method) 
        at java.lang.reflect.Method.invoke(Method.java:515) 
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:864) 
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:680) 
        at dalvik.system.NativeStart.main(Native Method) 
     Caused by: java.lang.ExceptionInInitializerError
        at okhttp3.OkHttpClient.newSslSocketFactory(OkHttpClient.java:263)
        at okhttp3.OkHttpClient.<init>(OkHttpClient.java:229)
        at okhttp3.OkHttpClient$Builder.build(OkHttpClient.java:1015)
        at com.facebook.react.devsupport.DevServerHelper.<init>(DevServerHelper.java:132)
        at com.facebook.react.devsupport.DevSupportManagerImpl.<init>(DevSupportManagerImpl.java:183)
        at java.lang.reflect.Constructor.constructNative(Native Method) 
        at java.lang.reflect.Constructor.newInstance(Constructor.java:423) 
        at com.facebook.react.devsupport.DevSupportManagerFactory.create(DevSupportManagerFactory.java:80) 
        at com.facebook.react.ReactInstanceManager.<init>(ReactInstanceManager.java:238) 
        at com.facebook.react.ReactInstanceManagerBuilder.build(ReactInstanceManagerBuilder.java:281) 
        at com.facebook.react.ReactNativeHost.createReactInstanceManager(ReactNativeHost.java:87) 
        at com.facebook.react.ReactNativeHost.getReactInstanceManager(ReactNativeHost.java:39) 
        at com.test2.MainApplication.onCreate(MainApplication.java:47) 
        at android.app.Instrumentation.callApplicationOnCreate(Instrumentation.java:1009) 
        at android.app.ActivityThread.handleBindApplication(ActivityThread.java:4614) 
        at android.app.ActivityThread.access$1800(ActivityThread.java:139) 
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1316) 
        at android.os.Handler.dispatchMessage(Handler.java:102) 
        at android.os.Looper.loop(Looper.java:136) 
        at android.app.ActivityThread.main(ActivityThread.java:5315) 
        at java.lang.reflect.Method.invokeNative(Native Method) 
        at java.lang.reflect.Method.invoke(Method.java:515) 
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:864) 
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:680) 
        at dalvik.system.NativeStart.main(Native Method) 
     Caused by: java.lang.IllegalStateException: Expected Android API level 21+ but was 19
        at okhttp3.internal.platform.AndroidPlatform.buildIfSupported(AndroidPlatform.java:238)
        at okhttp3.internal.platform.Platform.findPlatform(Platform.java:202)
        at okhttp3.internal.platform.Platform.<clinit>(Platform.java:79)
        at okhttp3.OkHttpClient.newSslSocketFactory(OkHttpClient.java:263) 
        at okhttp3.OkHttpClient.<init>(OkHttpClient.java:229) 
        at okhttp3.OkHttpClient$Builder.build(OkHttpClient.java:1015) 
        at com.facebook.react.devsupport.DevServerHelper.<init>(DevServerHelper.java:132) 
        at com.facebook.react.devsupport.DevSupportManagerImpl.<init>(DevSupportManagerImpl.java:183) 
        at java.lang.reflect.Constructor.constructNative(Native Method) 
        at java.lang.reflect.Constructor.newInstance(Constructor.java:423) 
        at com.facebook.react.devsupport.DevSupportManagerFactory.create(DevSupportManagerFactory.java:80) 
        at com.facebook.react.ReactInstanceManager.<init>(ReactInstanceManager.java:238) 
        at com.facebook.react.ReactInstanceManagerBuilder.build(ReactInstanceManagerBuilder.java:281) 
        at com.facebook.react.ReactNativeHost.createReactInstanceManager(ReactNativeHost.java:87) 
        at com.facebook.react.ReactNativeHost.getReactInstanceManager(ReactNativeHost.java:39) 
        at com.test2.MainApplication.onCreate(MainApplication.java:47) 
        at android.app.Instrumentation.callApplicationOnCreate(Instrumentation.java:1009) 
        at android.app.ActivityThread.handleBindApplication(ActivityThread.java:4614) 
        at android.app.ActivityThread.access$1800(ActivityThread.java:139) 
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1316) 
        at android.os.Handler.dispatchMessage(Handler.java:102) 
        at android.os.Looper.loop(Looper.java:136) 
        at android.app.ActivityThread.main(ActivityThread.java:5315) 
        at java.lang.reflect.Method.invokeNative(Native Method) 
        at java.lang.reflect.Method.invoke(Method.java:515) 
        at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:864) 
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:680) 
        at dalvik.system.NativeStart.main(Native Method) 
That's a useful answer
Without any help

Can you try running ./gradlew app:dependencies --configuration releaseRuntimeClasspath | grep okhttp in the android folder? It should give you the okhttp version used.