reminders-section: fix reminder alarm toggle button states

Alarm toggle state are in three stages because we do not update both
icon and active when pressed.

we now update the icons to match their states.

src/gui/event-editor/gcal-alarm-row.ui

@@ -7,6 +7,7 @@
         <property name="icon-name">audio-volume-high-symbolic</property>
         <property name="tooltip-text" translatable="yes">Toggle Alarm Sound</property>
         <signal name="notify::active" handler="on_sound_toggle_changed_cb" object="GcalAlarmRow" swapped="no" />
+        <property name="active">yes</property>
         <style>
           <class name="flat" />
         </style>

src/gui/event-editor/gcal-reminders-section.c

@@ -124,7 +124,7 @@ create_alarm (guint minutes)
 
   alarm = e_cal_component_alarm_new ();
   e_cal_component_alarm_take_trigger (alarm, trigger);
-  e_cal_component_alarm_set_action (alarm, E_CAL_COMPONENT_ALARM_DISPLAY);
+  e_cal_component_alarm_set_action (alarm, E_CAL_COMPONENT_ALARM_AUDIO);
 
   return alarm;
 }