REFACTOR: Remove an unnecessary `Discourse.__container__`

app/assets/javascripts/discourse/app/controllers/preferences/notifications.js

@@ -87,9 +87,6 @@ export default Controller.extend({
       },
       { name: I18n.t("user.new_topic_duration.last_here"), value: -2 }
     ];
-
-    const caps = Discourse.__container__.lookup("capabilities:main");
-    this.isIOS = caps.isIOS;
   },
 
   actions: {

app/assets/javascripts/discourse/app/templates/preferences/notifications.hbs

@@ -43,7 +43,7 @@
   </div>
 </div>
 
-{{#unless isIOS}}
+{{#unless capabilities.isIOS}}
   <div class="control-group desktop-notifications">
     <label class="control-label">{{i18n "user.desktop_notifications.label"}}</label>
     {{desktop-notification-config}}