NativeGestureUtil.notifyNativeGestureEnded is called

Summary:
Changelog: [Internal] - Make sure `onChildEndedNativeGesture` is called for view managers that call `onChildStartedNativeGesture`

This affects `JSTouchDispatcher`, `JSPointerDispatcher` as they track what view is reporting native gesturing handling.

This is a bug that view managers never shared the fact that they've stopped managing a native gesture. Both `JSTouchDispatcher`, `JSPointerDispatcher` get around this by manually resetting their internal flag on ACTION_DOWN event (we will get rid of this in a later diff)

Reviewed By: javache

Differential Revision: D38850609

fbshipit-source-id: ef4afb591249bb621f42667608dc1ef20424b65c

ReactAndroid/src/main/java/com/facebook/react/uimanager/JSPointerDispatcher.java

@@ -109,9 +109,6 @@ public class JSPointerDispatcher {
 
     // First down pointer
     if (action == MotionEvent.ACTION_DOWN) {
-
-      // Reset mChildHandlingNativeGesture like JSTouchDispatcher does
-      mChildHandlingNativeGesture = -1;
       mPrimaryPointerId = motionEvent.getPointerId(actionIndex);
 
       // Start a "down" coalescing key