Leanback: parallax and details video API refactoring

There are too many new concpets introduced when we create
multiple building blocks around parallax. This CL tries to
get rid of some classes.

1. Remove class ParallaxSource, integrated into Parallax.
So there is no more setSource()/getSource().

2. Replace DetailsParallaxManager with DetailsParallax. It is no
longer a manager pattern but DetailsParallax is a direct
subclass of Parallax.

3. Replace DetailsBackgroundParallaxHelper with
DetailsParallaxDrawable which is a direct subclass of
CompositeDrawble. No more helper concept.

4. remove the glue creation API from DetailsFragment, those
are not necessary and app can do it on the side.

The summary of new classes:
1. Parallax, tracks multiple UI events and perform multiple
ParallaxEffects on ParallaxTargets.  RecyclerViewParallax is a
subclass of Parallax that monitors RecyclerView child positions.

2. DetailsParallax is a subclass of RecyclerViewParallax,
DetailsFragment holds the DetailsParallax object and is responsible
to attach it to VerticalGridView and sync with Transition animation.
DetailsParallax is shared by both background bitmap and video.

3. Created a DetailsFragmentBackgroundController class responsible
for parallax background and embedded video playing.

Bug: 33750080
Bug: 33751156
Test: all existing leanback tests

Change-Id: Iec81a444d5d4fbeb675f16222b09b407acf007a2
38 files changed