Use RecyclerView for TV PiP menu buttons.

- Improved a11y messages: Talkback adds context of buttons (PiP menu)
  when focus switches to the RecyclerView + adds item position (X of X)
- Improved readability without switching between different ScrollViews
- Nicer scroll behavior at start and end than with Space elements
- Also fixes move menu arrows not updating when moving the PiP

Bug: 258652853
Test: manual - with and without Talkback: open PiP menu, enter/move/exit
move menu, expand/collapse PiP with and without orientation change, have
test app add and remove custom actions while the menu is open

Change-Id: Idbe4c2abce148d0fd5921371b1c95f8dafc3da5f
9 files changed