Apply edge-to-edge insets in A11yMenuSettingsActivity

Fix: 380054834
Test: open this page, observe preferences and top bar are not hidden by
      system / navigation bars; repeat for small/med/large font and
      display sizes
Flag: EXEMPT minor bugfix with resource changes
Change-Id: I3d2d3ee62ba521cc60e6836a1fd84ef42dd14100