Migrate away fully from MockitoJUnitRunner

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=192291786

javatests/google/registry/testing/MockitoJUnitRule.java

@@ -0,0 +1,45 @@
+// Copyright 2018 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.testing;
+
+import org.junit.rules.MethodRule;
+import org.junit.runners.model.FrameworkMethod;
+import org.junit.runners.model.Statement;
+import org.mockito.Mockito;
+import org.mockito.MockitoAnnotations;
+
+/** A rule that initializes Mockito-annotated fields (e.g. mocks and captors). */
+// TODO(b/77815684): Replace with native version from Mockito v1.10 once we upgrade to that.
+public class MockitoJUnitRule implements MethodRule {
+
+  public static MockitoJUnitRule create() {
+    return new MockitoJUnitRule();
+  }
+
+  @Override
+  public Statement apply(Statement base, FrameworkMethod method, Object target) {
+    return new Statement() {
+      @Override
+      public void evaluate() throws Throwable {
+        MockitoAnnotations.initMocks(target);
+        try {
+          base.evaluate();
+        } finally {
+          Mockito.validateMockitoUsage();
+        }
+      }
+    };
+  }
+}