Only ignore transition change of finishing transient launch

Since I52bb8ecbed7437107c776ad5fdd4b4d4d4d4f962
The visibility change when restoring transient launch is changed from
(2) to (1).
WindowOrganizerController's finishTransition
  (1) applyTransaction
  (2) t.finishTransition
So it is also in playing state.

With additional transient check, this would also reduce adding
the flag accidentally, such as swiping between app and home
multiple times very quickly.

Bug: 377427846
Flag: EXEMPT bugfix
Test: A task contains 2 activities. The first one calls sleep 300ms
      in onResume (easier to tap nav bar).
      Finish the top one and tap nav bar quickly.
      The transition should play normal activity switch animation
      instead of a jumpcut (disturbed by the change info of
      transient launch).
Change-Id: Id4fe5e0e2f907e68245442fa6a8dcd998caa9087