Ensuring that we don't start dragging while another drag is in progress.

Change-Id: If3c5a059407efc3ee9a0c9b1b3b7fb942d3a7664

src/com/android/launcher2/PagedViewWithDraggableItems.java

@@ -50,8 +50,9 @@ public abstract class PagedViewWithDraggableItems extends PagedView
     }
 
     protected boolean beginDragging(View v) {
+        boolean wasDragging = mIsDragging;
         mIsDragging = true;
-        return false;
+        return !wasDragging;
     }
 
     protected void cancelDragging() {