Add an 65% opacity for workspace elements drag over button drop target

Also remove the draggable item hover top button color change.

Test: Manual
Bug: 183193201
Change-Id: Id80622b8c0152180c47c0c9ebff8aa8bc2a5c2be

src/com/android/launcher3/DeleteDropTarget.java

@@ -53,9 +53,6 @@ public class DeleteDropTarget extends ButtonDropTarget {
     @Override
     protected void onFinishInflate() {
         super.onFinishInflate();
-        // Get the hover color
-        mHoverColor = getResources().getColor(R.color.delete_target_hover_tint);
-
         setDrawable(R.drawable.ic_remove_shadow);
     }