Fix license for XMoreLikeThis (#68851)

Author: jimczi

server/src/main/java/org/elasticsearch/common/lucene/search/XMoreLikeThis.java

@@ -1,17 +1,10 @@
-/*
- * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
- * or more contributor license agreements. Licensed under the Elastic License
- * 2.0 and the Server Side Public License, v 1; you may not use this file except
- * in compliance with, at your election, the Elastic License 2.0 or the Server
- * Side Public License, v 1.
- */
-
-/*
- * Copyright 2004-2005 The Apache Software Foundation.
- *
- * 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
+/* @notice
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You 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
  *
@@ -20,7 +13,10 @@
  * 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.
+ *
+ * Modifications copyright (C) 2020 Elasticsearch B.V.
  */
+
 package org.elasticsearch.common.lucene.search;
 
 import org.apache.lucene.analysis.Analyzer;