Fixing crash when changing state while all-apps is not complete bound

Change-Id: I564501244cb1478195e5d226da295c13269ff524

src/com/android/launcher3/allapps/AllAppsContainerView.java

@@ -392,7 +392,8 @@ public class AllAppsContainerView extends SpringRelativeLayout implements DragSo
     }
 
     public RecyclerViewFastScroller getScrollBar() {
-        return getActiveRecyclerView().getScrollbar();
+        AllAppsRecyclerView rv = getActiveRecyclerView();
+        return rv == null ? null : rv.getScrollbar();
     }
 
     public void setupHeader() {