Use separate thread if app doesn't listen to animations

There is no need to introduce jank risk and run the inset
animations on the main thread if the app doesn't listen to
animation events. In that case, move the animations onto a
separate thread.

Bug: 118118435
Test: Inspect systrace
Change-Id: Ib6e4b4ce8e9dd8e27761ced6eb8d7700b6236a32