Merge "Check for isAttachedToWindow before dispatching touch event" into main

quickstep/src/com/android/launcher3/taskbar/navbutton/NearestTouchFrame.java

@@ -194,6 +194,7 @@ public class NearestTouchFrame extends FrameLayout {
                 event.offsetLocation(mTouchingChild.getWidth() / 2 - x,
                         mTouchingChild.getHeight() / 2 - y);
                 return mTouchingChild.getVisibility() == VISIBLE
+                        && mTouchingChild.isAttachedToWindow()
                         && mTouchingChild.dispatchTouchEvent(event);
             }
         }