Refactoring WallpaperOffsetInterpolator to a new file

Removing some us unused methods

Change-Id: Ife790e5ca6848fa13dc3fab1bba1e6220bf83743

src/com/android/launcher3/AnotherWindowDropTarget.java

@@ -61,13 +61,4 @@ public class AnotherWindowDropTarget implements DropTarget {
     // These methods are implemented in Views
     @Override
     public void getHitRectRelativeToDragLayer(Rect outRect) {}
-
-    @Override
-    public void getLocationInDragLayer(int[] loc) {}
-
-    @Override
-    public int getLeft() { return 0; }
-
-    @Override
-    public int getTop() { return 0; }
 }