fix NPE when a touch event is sent to an unknown Android platform view (#9476)

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

@@ -192,11 +192,10 @@ public class PlatformViewsController implements PlatformViewsAccessibilityDelega
                 parsePointerCoordsList(touch.rawPointerCoords, density)
                     .toArray(new PointerCoords[touch.pointerCount]);
 
-            View view = vdControllers.get(touch.viewId).getView();
-            if (view == null) {
-                throw new IllegalStateException("Sending touch to an unknown view with id: "
-                    + touch.viewId);
+            if (!vdControllers.containsKey(touch.viewId)) {
+                throw new IllegalStateException("Sending touch to an unknown view with id: " + touch.viewId);
             }
+            View view = vdControllers.get(touch.viewId).getView();
 
             MotionEvent event = MotionEvent.obtain(
                 touch.downTime.longValue(),