I integrated React Native into an existing Android project. The code compiles fine, but when I get to the part of my app that initializes React Native, the app crashes.

Relevant part of the backtrace:

java.lang.RuntimeException: Requested enabled DevSupportManager, but DevSupportManagerImpl class was not found or could not be created
      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:77)
      Caused by: java.lang.reflect.InvocationTargetException
        at java.lang.reflect.Constructor.newInstance(Native Method)
        at com.facebook.react.devsupport.DevSupportManagerFactory.create(DevSupportManagerFactory.java:70)
      Caused by: java.lang.NoClassDefFoundError: com.facebook.react.bridge.JSPackagerWebSocketClient
        at com.facebook.react.devsupport.DevServerHelper.<init>(DevServerHelper.java:108)
        at com.facebook.react.devsupport.DevSupportManagerImpl.<init>(DevSupportManagerImpl.java:141)

The key part is

java.lang.NoClassDefFoundError: com.facebook.react.bridge.JSPackagerWebSocketClient.

I'm not sure why this class wouldn't be found. The location where this crash happens in the React Native source code is here.

UPDATE: If it's relevant, I was getting compile-time errors before this that I fixed with the solution here (which excludes okhttp-ws) which I wonder may be causing this.

UPDATE 2: I'm starting to think this is related to excluding okhttp-ws since I noticed in JSPackagerWebSocketClient.java there are imports such as:

import okhttp3.ws.WebSocket;

So I guess the real question is what is the real fix for the original issue I was having, which is:

com.android.build.api.transform.TransformException: java.util.zip.ZipException: duplicate entry: okhttp3/internal/ws/RealWebSocket$1.class

I'm using React Native v0.31.0.