We should schedule an update when the expansion changes

Since the shade is invisible when collapsed, we need
to update once in order to get the opening animation
working.

Change-Id: Ife0c2f704843b7916c33a5ee8e8e205f832fc631
Test: add notifications, open shade.
Fixes: 33773678

packages/SystemUI/src/com/android/systemui/statusbar/stack/NotificationStackScrollLayout.java

@@ -3179,6 +3179,7 @@ public class NotificationStackScrollLayout extends ViewGroup
             }
             updateNotificationAnimationStates();
             updateChronometers();
+            requestChildrenUpdate();
         }
     }