Animate the pointer when IME comes up

* Removes some unnecessary methods off Bubble, these can
  be called directly on the expanded view.
* Add some code to animate the pointer
* Fade the pointer with the TaskView

Test: manual - check that the pointer animates with the
               bubble when the IME comes in / out
Bug: 193911220
Change-Id: I477f34de3611eea79f933958ec6e09f68eb93179