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
1 file changed