Refactoring fast scroller.

- Fixing issue with fast scroller not fitting name width.
- Refactoring fast scrolling/scroll bar code out of base recycler view
- Adding animations to fast scroller to match design
- Smooth scrolling when jumping between app rows
- Fixing issue with fast scroller jumping when you first pick it up
- Fixing issue with wrong background paddings being used

Bug: 21874346
Bug: 22031923
Change-Id: I9f011b1f375751f437604b900e95a2942d3f4601