Switch Access focus on first item of power menu

Before this commit, the whole power menu used to take the focus and now
the first element of the list takes focus when navigating into power
menu with Switch Access.

Flag: NA
Fixes: 319209478
Test: Manual. With Switch Access on navigate to power menu. Instead of
      the whole box, the first item should be focused when entering the
      power menu.
Change-Id: I7a37bb8a552fecf7ba13dc09ce065bdd003fb58d