Elevate accessibility preference to root level on all flavors

Previews on Amati and Watson:
https://screenshot.googleplex.com/6pawiGR7LovZUc4
https://screenshot.googleplex.com/3MdTCwt5EM6aaGG

Test: Manually on Amati and Watson
Bug: 227737020
Change-Id: I3f103855ba0f9af8a134d9e964f44d6e27c0da9f
10 files changed