Draw SmartSelectSprite in TextView

Instead of the SmartSelectSprite drawing its contents into a View's
ViewOverlay, the SmartSelectSprite can now be drawn on any Canvas. In
order to perform the smart select animation, it is now the TextView that
performs the actual drawing.

Since the TextView can adjust the canvas for its padding and offset,
there is no more need to manually transform the selection rectangles, so
that part can be removed.

Test: manual - verify smart select animation still works
Change-Id: Ibaccf59fd44d5701e6f37d6b4fa97f2b05fd77cc