When overview appears from motion pause, come up from bottom

- Add vertical offset calculations to RecentsView (in addition to
  the existing horizontal offset which has been renamed accordingly).
- LauncherState#getOverviewScaleAndOffset() now supports both
  horizontal and vertical offsets and is specified such that overview
  appears and disappears from the bottom of the screen rather than the
  side.
- Quick switch still uses horizontal offset to come from the side.
- No longer need to scroll to page 0 when translating offscreen.
- Update interpolators for overview to home transition.
- Align 2 button mode transition with 0 button mode.

Test: Visually checking all of these. As appropriate, repeat in 0, 2, 3
button modes, landscape/portrait/fake landscape, and 3P launcher
- Quick switch from home
- Home to overview
- Overview to home (swipe up)
- Overview to home (tap outside)
- Overview to home (back invocation)
- Quick switch from app
- Swipe up and hold from app
- Dismiss an app
- Empty recents
- Split select state to home
- Modal state to home

Bug: 185411781
Change-Id: Ic59b877ccc0050afd7cd478778e9eeb60e2e47f7