Fixed a bug where the expand button was invisible

Since the view wasn't layouted yet it was layouting it wrongly

Change-Id: I62fcdde1eda457bab74765a290865b1749b08dac
Fixes: 28869354

packages/SystemUI/src/com/android/systemui/statusbar/NotificationContentView.java

@@ -264,6 +264,7 @@ public class NotificationContentView extends FrameLayout {
         invalidateOutline();
         selectLayout(false /* animate */, mForceSelectNextLayout /* force */);
         mForceSelectNextLayout = false;
+        updateExpandButtons(mExpandable);
     }
 
     @Override