Update size constraints on aspect ratio change

With the recent change ag/26603167, PipController could miss the chance
to update the size constraints. As a result,
PipResizeGestureHelper#finishResize uses staled max size information at
the end of pinch-resize.

It's fixed in this CL as to let PipTouchHandler subscribe to aspect
ratio from PipBoundsState, which serves as the source of truth.

Long term, we should cleanup / consolidate the logic right now scatter
in PipTaskOrganizer / PipController / etc.

Video: http://recall/-/aaaaaabFQoRHlzixHdtY/kZmKG4c8SiBS7fjg67Qek
Bug: 335311217
Test: manual, follow the reproduce steps
Change-Id: Ie5c7ad2536ecbbf6c1a015b60328de30dae7e10e