Cancel back invoke when window focus has lost

This reverts commit 0099ca8f and provide
new mechanism.

The back invoke target could lost focus during back navigation gesture.
To prevent the non-focused window could still trigger back action cause
some unexpected behavior, this CL will listen the focus change of
current focused window and cancel back gesture when its focus has lost.

Bug: 238050065
Bug: 239792909
Test: atest BackNavigationControllerTests
Test: atest BackNavigationLegacyGestureTest BackNavigationLegacyTest
Test: atest BackNavigationTests
Test: atest WindowOnBackInvokedDispatcherTest BackNavigationTest
Test: atset BackAnimationControllerTest

Change-Id: I65eb19371020ce39977eeb2a2a80c7f08600aaec