Move bounds calculation and snap fraction to SysUI

Major changes in this CL

- Added PipBoundsHandler in SysUI package handles the bounds calculation
and save/restore the snap fraction
- Added IPinnedStackListener.onSaveReentrySnapFraction and
IPinnedStackListener.onResetReentrySnapFration, both called from
PinnedStackController (WM) to SysUI
- Added IPinnedStackListener.onPrepareAnimation, called from WM to
SysUI to notify that an animation for pinned stack is about to happen
- Added IPinnedStackController.startAnimation, called from SysUI to WM
to actually start the pinned stack animation
- Updated tv/PipManager to use PipBoundsHandler as well

Known issues and what's next

- Shelf height is set after the animation is started, therefore one may
notice the PiP window is hovering over the shelf. This is tracked
separatedly by b/139016518
- Bounds calculations still exist in PinnedStackController since
onTaskStackChanged callback requires so. Once we addressed b/139016833
(move rotation bounds calculation to SysUI), they should be all gone.
- Move the pinned stack animation from WM to SysUI and we can furthre
remove IPinnedStackListener.onPrepareAnimation and
IPinnedStackController.startAnimation

More details: go/pip-sysui-migration

Bug: 139015463
Bug: 139015142
Test: atest PinnedStackTests
Test: atest PinnedStackControllerTest
Change-Id: I76c2b40ea0fe95e3a8019b434d39ba5540e2039f