Fix UnfoldAnimationControllerTest

With ag/20738721, the surface's reset iff there is a state change.
Update the UnfoldAnimationControllerTest accordingly and also decouple
it from pinned task.

Bug: 261996076
Test: atest UnfoldAnimationControllerTest
Change-Id: I7de0733315f54c78e504785fb612c946d98ea38c