Set mState = mCurrentStableState in onAnimationCancel

mState is set when the transition starts toward that state even if it is
never reached. If the animation is canceled, therefore, we should reset
mState = mCurrentStableState since that is the state we came from.

For instance, when swiping up from overview, mState = ALL_APPS, but when
swiping back down we cancel that animation and create the task launch
animation. When creating the task launch animation, we reapplyState(),
which, before this change, was still ALL_APPS instead of OVERVIEW.

Bug: 79935289
Change-Id: I59c5799e92350747e4ef1d99a80ba678a2ce7b98