Handle IME user animation in ImeTracker

This enables tracking user animation IME requests in ImeTracker.
User animations can take an undetermined amount of time, so they could
easily time out. We should mark these finished as soon as we dispatch
control to the requester, with a new onDispatched call.

Bug: 328034080
Test: logcat while tapping on launcher google search
Change-Id: I9ae3494c044aebdcb74365d8b23a20b4f426f9bd