No-op queued transition if display chng populating

If a transition is queued when a display changing transition
is still collecting and hasn't been "populated"/"formally started"
yet, then make sure we send that transition to Shell as no-op
where it will be aborted
Do this when once the transition starts collecting
when being popped off the queue.

Bug: 409386802
Flag: EXEMPT bugfix
Test: atest PinnedStackTests#testPinnedStackInBoundsAfterRotation
Change-Id: I0c4a242cfe9209c4b5e5309b32e139fc4abcb253