Add crossfade animation on finish resize

If seamless resize is enabled and the pip param for it is set to false,
the finish resize transaction will do a crossfade animation between the
two states.

Bug: 152554547
Test: corner/drag resize or tap to expand, stretch resize crossfade when let go
Change-Id: I8b2b27335ab8150a84914fc29615dd6625b1af35