Fixed another memory leak

Clicked heads-up notifications were never released

Test: runtest systemui
Change-Id: I9a1097fd5d26caca25c784905b60ea4b40468b2f
diff --git a/packages/SystemUI/src/com/android/systemui/statusbar/stack/NotificationStackScrollLayout.java b/packages/SystemUI/src/com/android/systemui/statusbar/stack/NotificationStackScrollLayout.java
index 48dbe49..d3b336b 100644
--- a/packages/SystemUI/src/com/android/systemui/statusbar/stack/NotificationStackScrollLayout.java
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/stack/NotificationStackScrollLayout.java
@@ -3416,6 +3416,7 @@
         for (View view : mClearOverlayViewsWhenFinished) {
             StackStateAnimator.removeFromOverlay(view);
         }
+        mClearOverlayViewsWhenFinished.clear();
     }
 
     private void runAnimationFinishedRunnables() {