Split ResourceAlreadyExistsException based on if this client owns the resource

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=250728711

java/google/registry/flows/exceptions/ResourceCreateContentionException.java

@@ -0,0 +1,27 @@
+// 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.flows.exceptions;
+
+import google.registry.flows.EppException.ObjectAlreadyExistsException;
+
+/** Resource with this id already exists. */
+// This is different from ResourceAlreadyExistsForThisClientException in that this is used in
+// resource creation contention situations, where another client owns this resource. Javadoc and
+// exception message are the same for backcompat purposes.
+public class ResourceCreateContentionException extends ObjectAlreadyExistsException {
+  public ResourceCreateContentionException(String resourceId) {
+    super(String.format("Object with given ID (%s) already exists", resourceId));
+  }
+}