Ensure that TouchEvent is initialized with a valid MotionEvent

Summary:
It is unlikely but possible that the crash T94864568 is caused by a TouchEvent being initialized with a null MotionEvent. Regardless, we should guard against this case.

Changelog: [Internal]

Reviewed By: ShikaSD

Differential Revision: D29594750

fbshipit-source-id: 3a409b716a9f1eec8017002ae7e23273677e53ba

ReactAndroid/src/main/java/com/facebook/react/uimanager/events/TouchEvent.java

@@ -43,7 +43,7 @@ public class TouchEvent extends Event<TouchEvent> {
         -1,
         viewTag,
         touchEventType,
-        motionEventToCopy,
+        Assertions.assertNotNull(motionEventToCopy),
         gestureStartTime,
         viewX,
         viewY,
@@ -67,7 +67,7 @@ public class TouchEvent extends Event<TouchEvent> {
         surfaceId,
         viewTag,
         touchEventType,
-        motionEventToCopy,
+        Assertions.assertNotNull(motionEventToCopy),
         gestureStartTime,
         viewX,
         viewY,