Update SettingsPanel UI

UI changes include:
- RecyclerView to host slices
- Font family to headline font
- Title is now centered
- Added SeeMore & Done buttons
- Horizontal Dividers between slices
- Indented Slices
- Landscape layout is fullscreen

Change-Id: I3549c847fc88edd81f670ddfa2907dd3741441e0
Screenshot: https://screenshot.googleplex.com/RzWktzOZJkc
Test: Robolectric
Test: Manual app
Bug: 118622007