Don't resize PiP on aspect ratio change if nothing changed.

Aspect ratio changes could be deferred, and thus only the aspect ratio
itself needs to be updated, but the bounds itself is already correct.

Bug: 234615306
Bug: 241096069
Test: Enter PiP and move it around right after animation finishes
Change-Id: Ia1078a6492358e694d4eadf97fa0f242a4033c6f