Add visual indicator for predicted hotseat icons

Bug: 142753423
Test: Manual
Change-Id: Ie4325660fc5392358ec845ae58385bef279db60f

src/com/android/launcher3/BubbleTextView.java

@@ -216,6 +216,7 @@ public class BubbleTextView extends TextView implements ItemInfoUpdateReceiver,
         cancelDotScaleAnim();
         mDotParams.scale = 0f;
         mForceHideDot = false;
+        setBackground(null);
     }
 
     private void cancelDotScaleAnim() {