this is but the most glaringly obvious problem with the keyboard selection.
in order for the controller to set a new layout it needs a call to
update the layout AND to update the variant within that layout. due to the
way the signals are managed we only ever sent the former on layout changes
which results in the changes not actually applying to the running system.
when changing the layout the variants list gets updated as well, we'll
simply force a variant application at this time. generally the choices only
change when the layout changed, so this should be the soundest possible
place to force the update