Wire in MetricsReporter to FrontendServlet

This work is identical to the work done for BackendServlet in
[]

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=132100448

java/google/registry/module/frontend/FrontendMetricsModule.java

@@ -0,0 +1,25 @@
+// Copyright 2016 The Domain Registry Authors. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package google.registry.module.frontend;
+
+import dagger.Module;
+import javax.inject.Singleton;
+
+/**
+ * Dagger module for injecting metrics. All metrics should have {@link Singleton} scope to avoid
+ * being recreated per-request, as the metrics generally track cumulative values.
+ */
+@Module
+public class FrontendMetricsModule {}