Avoid potential re-entry as a result of child mutation

Don't set the callback until we're all done making changes.

Bug: 30902893
Change-Id: Ia1560692a83ecb2c50f5e77fa4d1e8155a78a204
(cherry picked from commit b46ba3b2b0)

graphics/java/android/graphics/drawable/DrawableContainer.java

@@ -851,8 +851,8 @@ public class DrawableContainer extends Drawable implements Drawable.Callback {
 
         private Drawable prepareDrawable(Drawable child) {
             child.setLayoutDirection(mLayoutDirection);
-            child.setCallback(mOwner);
             child = child.mutate();
+            child.setCallback(mOwner);
             return child;
         }