polkit.addRule(function(action, subject) {
    if ((action.id == "org.freedesktop.packagekit.upgrade-system" ||
         action.id == "org.freedesktop.packagekit.trigger-offline-update") &&
        subject.active == true && subject.local == true &&
        subject.isInGroup("sudo")) {
            return polkit.Result.YES;
    }
});