copy motion event and re-use it as it gets mutated later

Author: Kaushik Iska

shell/platform/android/io/flutter/embedding/android/MotionEventTracker.java

@@ -50,7 +50,7 @@ private MotionEventTracker() {
   /** Tracks the event and returns a unique MotionEventId identifying the event. */
   public MotionEventId track(MotionEvent event) {
     MotionEventId eventId = MotionEventId.createUnique();
-    eventById.put(eventId.id, event);
+    eventById.put(eventId.id, MotionEvent.obtain(event));
     unusedEvents.add(eventId.id);
     return eventId;
   }

shell/platform/android/io/flutter/plugin/platform/PlatformViewsController.java

@@ -329,12 +329,10 @@ public MotionEvent toMotionEvent(
             .toArray(new PointerCoords[touch.pointerCount]);
 
     if (!usingVirtualDiplays && trackedEvent != null) {
-      // TODO (kaushikiska): investigate why we can not use the tracked
-      // event directly.
       return MotionEvent.obtain(
           trackedEvent.getDownTime(),
           trackedEvent.getEventTime(),
-          touch.action,
+          trackedEvent.getAction(),
           touch.pointerCount,
           pointerProperties,
           pointerCoords,