Ensure TaskOrganizer works for newly created pinned stack

Steps to reproduce the bug:
- Restart the device
- Open Duo app and make a call
- When in call, try entering PiP

Duo application contains multiple activities and we create a new stack
from its top activity when moving it to pinned mode. This newly created
stack does not carry on the existing PictureInPictureParams, nor it is
marked as visible. Therefore, no onTaskAppeared would be sent to the
task organizer.

Also in this change:
- Removed aspectRatio and sourceHintBounds used to be passed into
  RootWindowContainer#moveActivityToPinnedStack, they are used in
  moveActivityToPinnedStack and one should refer to the
  PictureInPictureParams set on ActivityRecord
- Added a null check for existing token when onTaskInfoChanged is
  invoked in PipTaskOrganizer, it should be a fatal error that
  onTaskInfoChanged is called ahead of onTaskAppeared

Bug: 152933995
Test: manually enter/exit PiP mode for Duo app
Test: atest RootActivityContainerTests
Test: atest ActivityRecordTests
Change-Id: Ifa9ad8768ba47ce043b8dd86cadc729931edcb14