Some tuning for MultiWaveView animations and assets:

- allow individual chevrons to be specified for (top, bottom, left, right).
- move ring to pressed position (currently w/o animation)
- add top/bottom chevron handling and refactor code accordingly.
- constrain drag handle to the ring

Change-Id: I859b2d03d8f0397c68b87a8ee15df20d55c9552c