[PB] Always cleanup fixed rotation when finish predictive back animation

Always reset FixedRotationLaunchingApp when finish animation.
Also, if animation target is for predictive back, ignore
dispatchLegacyAppTransitionFinished which will reset the
mLauncherTaskBehind, so core won't trigger configuration change twice
due to ensureActivitiesVisible happen before global configuration
change.

Flag: EXEMPT bugfix
Bug: 347497084
Test: atest BackNavigationControllerTests BackGestureInvokedTest
Test: verify fixed rotation will be reset after every type of animation
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:0654191f7a8f669a2a018387cf50dac3db99be40)
Merged-In: I10012d558f3c302f90129a3df72f568fa5795651
Change-Id: I10012d558f3c302f90129a3df72f568fa5795651