Create accessibility menu for bubble bar

Bug: 344670180
Test: open accessibility action menu on bubble bar. use menu to
  - expand bubble bar
  - dismiss bubble bar
Test: when bubble bar is on the right, the action menu has an option to
  move bubble bar to the left only, use menu to move bar to the left
Test: when bubble bar is on the left, the action menu has an option to
  move bubble bar to the right only, use menu to move bar to the right
Flag: com.android.wm.shell.enable_bubble_bar
Change-Id: Id875a43927bc3410a83d1342b9456330c9521085