Check the magnification state before performing onAnimationEnd

onAnimationEnd will be called when we call cancel() on the animator.
Therefore, we need to confirm the the expected state in onAnimationEnd
for the following actions.

Bug: 389083496
Test: atest FullscreenMagnificationControllerTest
Flag: EXEMPT bugfix
Change-Id: I8379aadc140c00657e0b8ac8177da6961f6f2b09