New Shimmy

- Two step shimmy: first show the mode switcher, then hide it
  with a shimmy animation.
- Hiding will not start until after all the popups are dismissed

TODO:
- When mode switcher is shown for shimmy, text should be hidden (
  this involves cooridnating the timing to show text with user
  interaction)
- Need to have a graceful transition if user grabs the list on its
  way out

Bug: 13183433
Change-Id: Idda5520c3c3663864be0f478787ef603fdb0f6da
3 files changed