Change home dragging logic for dead zones

- If a dragged item is not over a valid drop target
then we don't highlight anything and on drop we move
it back to its original position.
- Instead of checking if the dragged item is over the
hotseat view, now we check if the item is over the hotseat
shortcuts.
- Smartspace is a dead zone

Test: drag items from different workspaces, allapps, widget
  picker etc. to all parts of the screen and verify which
  view is targeted and where the item gets dropped.
  Check on phone/foldable/tablet.
Bug: 228201267
Change-Id: I18de576ea300d58ae645e511b238e0b946b5595a

src/com/android/launcher3/views/BaseDragLayer.java

@@ -412,6 +412,14 @@ public abstract class BaseDragLayer<T extends Context & ActivityContext>
                 coord, includeRootScroll);
     }
 
+    /**
+     * Similar to {@link #mapCoordInSelfToDescendant(View descendant, float[] coord)}
+     * but accepts a Rect instead of float[].
+     */
+    public void mapRectInSelfToDescendant(View descendant, Rect rect) {
+        Utilities.mapRectInSelfToDescendant(descendant, this, rect);
+    }
+
     /**
      * Inverse of {@link #getDescendantCoordRelativeToSelf(View, float[])}.
      */