Deem a change as independent if reparented

This is needed because during reparenting
promotion to the current parent is skipped
as the Shell might want to animate the transfer
from one parent to another. But then, this means
setupStartState() might end up setting crops of
both child and parent.

Bug: 333783235
Test: manually swipe up to auto-enter PiP
Change-Id: I9233d61263a42af91a0050489699adee7ce2fc05