CreateAlarmTool
Creates a clock alarm by firing an AlarmClock.ACTION_SET_ALARM intent at the system clock app (with EXTRA_SKIP_UI, so no UI is shown). Optional message label and days (comma-separated mon..sun) for a repeating alarm; omit days for a one-time alarm.
Requires the com.android.alarm.permission.SET_ALARM permission (declared in the manifest; a normal install-time permission). Reading existing alarms is not possible via any standard API.
Result keys: success, hour, minute, message, days.