Notify recents transition when a mixed keyguard-recents transition is consumed

- Launcher expects that a recents transition will always be started or
  canceled (unless it finishes it itself), but when a mixed recents
  transition is started, the mixed transition currently will be consumed
  without notifying the underlaying recents transition if this is a
  keyguard mixed transition

Fixes: 329324086
Test: Artificially trigger aborting a mixed transition and verify the
      recents transition is cleaned up
Change-Id: I6e88c5dd6ef067c289ad51d68ee35b09e53ae617