Initial, easy changes to support later addition of RDAP metrics

I split this out to avoid having a giant CL that changes everything. The actual
metrics will follow later.

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=174356874

java/google/registry/rdap/RdapMetrics.java

@@ -0,0 +1,31 @@
+// Copyright 2017 The Nomulus 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.rdap;
+
+/** RDAP Instrumentation. */
+public class RdapMetrics {
+
+  enum EndpointType {
+    AUTNUM,
+    DOMAIN,
+    DOMAINS,
+    ENTITY,
+    ENTITIES,
+    HELP,
+    IP,
+    NAMESERVER,
+    NAMESERVERS
+  }
+}