Controls UI - GAR adjustments

ToggleRange is a unique type of control, and needs custom logic to
deal with for TalkBack. Handle by using ACTION_SET_PROGRESS events to
let the user enter a specific amount.

Bug: 151231074
Test: Talkback
Change-Id: Ic8764a9a0e5cda62d1d9b9d5ff88289181ba3b17