Simplifying logic to create/destroy hardware layers in All Apps

Bug # 3422984

src/com/android/launcher2/PagedViewCellLayout.java

@@ -141,6 +141,7 @@ public class PagedViewCellLayout extends ViewGroup implements Page {
     public void removeAllViewsOnPage() {
         mChildren.removeAllViews();
         mHolographicChildren.removeAllViews();
+        destroyHardwareLayers();
     }
 
     @Override