QS: Only hide grid if there is detail to show

If the animation ends at the 'same' time as handleShowDetail is
running it is possible for the grid content to get cleared by the
animation callback just after it is shown in handleShowDetail.
This checks mDetailRecord to avoid that chance.

Bug: 18009138
Change-Id: Ia2951f44b5a1470321bf6580daf33917bbcb1ffd

packages/SystemUI/src/com/android/systemui/qs/QSPanel.java

@@ -542,7 +542,10 @@ public class QSPanel extends ViewGroup {
 
         @Override
         public void onAnimationEnd(Animator animation) {
-            setGridContentVisibility(false);
+            // Only hide content if still in detail state.
+            if (mDetailRecord != null) {
+                setGridContentVisibility(false);
+            }
         }
     };