These preferences are already set by the Clock app but are tracked completely separately also here which it sets by a D-Bus call; this indicator should just reuse the GSettings values upon the summoning of an alarm.
Currently this has resulted in a mismatch of the state machines between this indicator and clock app due to the D-Bus communication being blocked by AppArmor: https://gitlab.com/ubports/development/apps/lomiri-clock-app/-/issues/180.