Merge "Fix bug where two items could occupy same grid cell in hotseat." into ub-launcher3-master

src/com/android/launcher3/Workspace.java

@@ -421,6 +421,7 @@ public class Workspace extends PagedView
         }
 
         updateChildrenLayersEnabled();
+        mDragInfo = null;
         mOutlineProvider = null;
         mDragSourceInternal = null;
     }