Sets Drawable in DrawableWrapper properly

Before this change, creating a DrawableWrapper (through a custom class
that extends it) using the public constructor will not set the drawable
callback properly and DrawableWrapper will not update when the
underlying Drawable is invalidated.

Test: CTS test added
Bug: 120835632
Change-Id: I3545db76e032c0bd074846e0fa64c5cf01e2941c

graphics/java/android/graphics/drawable/DrawableWrapper.java

@@ -65,7 +65,7 @@ public abstract class DrawableWrapper extends Drawable implements Drawable.Callb
      */
     public DrawableWrapper(@Nullable Drawable dr) {
         mState = null;
-        mDrawable = dr;
+        setDrawable(dr);
     }
 
     /**