When dragging items on the home screen, visualize where they will drop.

Draw a rectangle around the area where an item will land if it is dropped.
If the area is vacant, the rectangle is green; otherwise, it is red.

Change-Id: I859b52514566fa55f8c7a04493b8088d12baa476
diff --git a/src/com/android/launcher2/Launcher.java b/src/com/android/launcher2/Launcher.java
index 03066c1..94556be 100644
--- a/src/com/android/launcher2/Launcher.java
+++ b/src/com/android/launcher2/Launcher.java
@@ -1088,7 +1088,7 @@
             outState.putInt(RUNTIME_STATE_PENDING_ADD_COUNT_X, layout.getCountX());
             outState.putInt(RUNTIME_STATE_PENDING_ADD_COUNT_Y, layout.getCountY());
             outState.putBooleanArray(RUNTIME_STATE_PENDING_ADD_OCCUPIED_CELLS,
-                   layout.getOccupiedCells());
+                   layout.getOccupiedCellsFlattened());
         }
 
         if (mFolderInfo != null && mWaitingForResult) {