Add workaround for PiP1 in sync-finished detection

To conservatively determine when a sync is finished (without
ready-tracking), we need to wait until visibility is calculated
after lifecycle events "settle". Unfortunately, pip1 is
sensitive to the time-spent waiting for lifecycle events to
complete (since it needs a "cleanup" transition to undo
an intermediate state it put WM in).

Until we have pip2, this CL works around this issue by
detecting this intermediate state and not-waiting. While
this technically creates a "gap" in ready detection, in
practice this situation should be rare outside of the
pip1 use-case.

Bug: 385852312
Test: 3btn-nav, go to pip, open another app, expand pip, re-enter
      pip quickly.
Flag: EXEMPT bugfix
Change-Id: Ic2f4a717d0d1c6429fc1eca9dfec27c00e9aa8c0