Storage: HMAC service account support

.kokoro/continuous/storage-it.cfg

@@ -25,3 +25,8 @@ env_vars: {
     key: "GOOGLE_APPLICATION_CREDENTIALS"
     value: "keystore/73713_java_it_service_account"
 }
+
+env_vars: {
+    key: "IT_SERVICE_ACCOUNT_EMAIL"
+    value: "[email protected]"
+}

.kokoro/nightly/storage-it.cfg

@@ -25,3 +25,8 @@ env_vars: {
     key: "GOOGLE_APPLICATION_CREDENTIALS"
     value: "keystore/73713_java_it_service_account"
 }
+
+env_vars: {
+    key: "IT_SERVICE_ACCOUNT_EMAIL"
+    value: "[email protected]"
+}

.kokoro/presubmit/storage-it.cfg

@@ -25,3 +25,8 @@ env_vars: {
     key: "GOOGLE_APPLICATION_CREDENTIALS"
     value: "keystore/73713_java_it_service_account"
 }
+
+env_vars: {
+    key: "IT_SERVICE_ACCOUNT_EMAIL"
+    value: "[email protected]"
+}

google-cloud-clients/google-cloud-contrib/google-cloud-nio/src/main/java/com/google/cloud/storage/contrib/nio/testing/FakeStorageRpc.java

@@ -18,6 +18,8 @@
 
 import com.google.api.services.storage.model.Bucket;
 import com.google.api.services.storage.model.BucketAccessControl;
+import com.google.api.services.storage.model.HmacKey;
+import com.google.api.services.storage.model.HmacKeyMetadata;
 import com.google.api.services.storage.model.Notification;
 import com.google.api.services.storage.model.ObjectAccessControl;
 import com.google.api.services.storage.model.Policy;
@@ -67,6 +69,7 @@
  *         <li>checksums, etags
  *         <li>IAM operations
  *         <li>BucketLock operations
+ *         <li>HMAC key operations
  *       </ul>
  * </ul>
  */
@@ -420,6 +423,31 @@ public List<BucketAccessControl> listAcls(String bucket, Map<Option, ?> options)
     throw new UnsupportedOperationException();
   }
 
+  @Override
+  public HmacKey createHmacKey(String serviceAccountEmail) {
+    throw new UnsupportedOperationException();
+  }
+
+  @Override
+  public Tuple<String, Iterable<HmacKeyMetadata>> listHmacKeys(Map<Option, ?> options) {
+    throw new UnsupportedOperationException();
+  }
+
+  @Override
+  public HmacKeyMetadata updateHmacKey(HmacKeyMetadata hmacKeyMetadata) {
+    throw new UnsupportedOperationException();
+  }
+
+  @Override
+  public HmacKeyMetadata getHmacKey(String accessId) {
+    throw new UnsupportedOperationException();
+  }
+
+  @Override
+  public void deleteHmacKey(String accessId) {
+    throw new UnsupportedOperationException();
+  }
+
   @Override
   public ObjectAccessControl getDefaultAcl(String bucket, String entity) {
     throw new UnsupportedOperationException();