Add Cloud KMS based secret storage

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=147791972

javatests/google/registry/model/server/KmsSecretRevisionTest.java

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+// 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.model.server;
+
+import static com.google.common.truth.Truth.assertThat;
+import static google.registry.model.ofy.ObjectifyService.ofy;
+import static google.registry.testing.DatastoreHelper.persistResource;
+
+import com.google.common.base.Strings;
+import google.registry.testing.AppEngineRule;
+import google.registry.testing.ExceptionRule;
+import org.junit.Before;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.JUnit4;
+
+@RunWith(JUnit4.class)
+public class KmsSecretRevisionTest {
+
+  @Rule public final AppEngineRule appEngine = AppEngineRule.builder().withDatastore().build();
+
+  @Rule public final ExceptionRule thrown = new ExceptionRule();
+
+  private KmsSecretRevision secretRevision;
+
+  @Before
+  public void setUp() {
+    secretRevision =
+        persistResource(
+            new KmsSecretRevision.Builder()
+                .setKmsCryptoKeyVersionName("foo")
+                .setParent("bar")
+                .setEncryptedValue("blah")
+                .build());
+  }
+
+  @Test
+  public void test_setEncryptedValue_tooLong_throwsException() {
+    thrown.expect(IllegalArgumentException.class, "Secret is greater than 67108864 bytes");
+    secretRevision =
+        persistResource(
+            new KmsSecretRevision.Builder()
+                .setKmsCryptoKeyVersionName("foo")
+                .setParent("bar")
+                .setEncryptedValue(Strings.repeat("a", 64 * 1024 * 1024 + 1))
+                .build());
+  }
+
+  @Test
+  public void testPersistence() {
+    assertThat(ofy().load().entity(secretRevision).now()).isEqualTo(secretRevision);
+  }
+}