Polish entering pip from fullscreen with shell transition

It was flickering by not considering the source hint rect
(offset becomes black area), non-scaled surface, and when
applying PiP bounds, the app doesn't draw with bounds change
synchronously.

Also pass source hint Rect for exiting pip animation so
the content won't be always scaled.

Bug: 277452732
Test: Swipe an app uses auto-pip with valid source hint.

Change-Id: If438fa81159b5a5a2bdb7c993c63c6f9dd514b99