Make on-screen keyboard settings support tab layout

Introduces following fragments for work flow.

- Add ProfileSelectKeyboardFragment which used to display
  personal/work fragment when user has work profile.
- Introduce UserAwareContext in AvailableVirtualKeyboardFragment
  to support personal/work user installed input methods handling.

Bug: 174360557
Bug: 197707782
Test: Manual test as bug video
Change-Id: I1019e375c5d42de7bc7c048d5d66e8e2f58acce8