[PiP2] End overlay animation if user interacts

If source-rect-hint is not valid we run an app icon
overlay fadeout animation after entering PiP.

But with PiP2 using config-at-end transitions we actually
allow users to interact with PiP earlier after entry than in PiP1.
So if PiP is resized or tap-con-to-expand is triggered, overlay's
offset and transform isn't really adjusted to reflect the new follow-up
transitions with new buffer sizes.

So we take the approach of just ending the overlay fadeout animation if
needed when either EXITING_PIP or when we have SCHEDULED_BOUNDS_CHANGE.

Bug: 399512881
Flag: com.android.wm.shell.enable_pip2
Test: enter PiP with wrong src-rect-hint, then tap app icon to reopen
Test: enter PiP with wrong src-rect-hint, then pinch-resize after
Change-Id: Icc0fb90bcac53b7e9e0df293f77dd37c88aadd92