Fix Snackbar swipe to dismiss not working pre-v11

Multiple issues:
- offsetTopAndBottom doesn't invalidate pre-v11, so
  ViewDragHelper now uses the ViewCompat version.
- ViewCompat's offset method needs to invalidate the parent
  instead, since the view has moved and thus the dirty rect
  is larger than the view's bounds.
- Fixed issue in Snackbar which meant that the view would
  not be removed after a swipe settle.

BUG: 26768803
Change-Id: Ia9abc4884f8ffd05408135d3fc4dd1b073392a7b
5 files changed