Remove some appengine dependencies (#1874)

Some retriers are no longer needed because transactions are
automatically retried by the JPA transaction manager when there's a
transient exception.

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util/src/main/java/google/registry/util/DatastoreServiceUtils.java

@@ -1,27 +0,0 @@
-// 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.util;
-
-import com.google.appengine.api.datastore.Key;
-import java.util.Optional;
-
-/** Utility methods for working with the App Engine Datastore service. */
-public class DatastoreServiceUtils {
-
-  /** Returns the name or id of a key, which may be a string or a long. */
-  public static Object getNameOrId(Key key) {
-    return Optional.<Object>ofNullable(key.getName()).orElse(key.getId());
-  }
-}