Refactor LauncherAppTransitionManager & polish for new app transitions.

* Add start delay when launcher resumes from all apps or landscape.
* Track the last app transition animator and cancel it before beginning a new one,
  otherwise the animators can conflict with each other.
  ie. Opening an app from all apps and then immediately pressing back to return to
      all apps.
* Use class overrride instead of UiFactory.

Bug: 70220260
Change-Id: I4755d45d820f9d551e443d6c4a148e8789c5bc57