Fix PiP regression when the stack animation is canceled

- We should immediately run the animation-end logic when the PiP animation
  is canceled and the final resize does not happen. Also ensure we call
  this animation end logic when not running a PiP animation (though nothing
  currently does this).

Bug: 109712078
Test: Enter PiP from a landscape app, ensure that the animation state is
      cleared
Test: atest CtsActivityManagerDeviceTestCases:ActivityManagerPinnedStackTests

Change-Id: Icd559a5377215eddc5fa4b1d3629d914396d9a3d