Hide the settings button on a notification in MNC.

ui/arc/notification/arc_notification_manager.cc

Index: ui/arc/notification/arc_notification_manager.cc
diff --git a/ui/arc/notification/arc_notification_manager.cc b/ui/arc/notification/arc_notification_manager.cc
index b4619203a7c13360a170dc3f7952d950bf5b83ef..1ec3b8f8c0d783f4b8466ccc72a23c7109161dc2 100644
--- a/ui/arc/notification/arc_notification_manager.cc
+++ b/ui/arc/notification/arc_notification_manager.cc
@@ -240,6 +240,12 @@ void ArcNotificationManager::OpenNotificationSettings(const std::string& key) {
   notifications_instance->OpenNotificationSettings(key);
 }
 
+bool ArcNotificationManager::IsOpeningSettingsSupported() const {
+  const auto* notifications_instance = ARC_GET_INSTANCE_FOR_METHOD(
+      arc_bridge_service()->notifications(), OpenNotificationSettings);
+  return notifications_instance != nullptr;
+}
+
 void ArcNotificationManager::OnToastPosted(mojom::ArcToastDataPtr data) {
   const base::string16 text16(
       base::UTF8ToUTF16(data->text.has_value() ? *data->text : std::string()));