Creating a separate view for FastScrollBar and moving all the relavant logic in
the view.
For protrait, the touch handling is delegated by the recycler view just like before.
For landscape, the dcrollbar does not overlay with recyclerView and handles the touch
itself
Bug: 37015359
Change-Id: Ie1981326457ba739bdf0ac8063db1065f395f133
Sunny Goyal