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
diff --git a/res/values/config.xml b/res/values/config.xml
index 2096200..3dddac2 100644
--- a/res/values/config.xml
+++ b/res/values/config.xml
@@ -92,6 +92,9 @@
     <!-- Name of a user event dispatcher class. -->
     <string name="user_event_dispatcher_class" translatable="false"></string>
 
+    <!-- Name of an app transition manager class. -->
+    <string name="app_transition_manager_class" translatable="false"></string>
+
     <!-- Name of a color extraction implementation class. -->
     <string name="color_extraction_impl_class" translatable="false"></string>