Add missing header

api/src/main/java/org/apache/cloudstack/backup/BackupPolicyVMMap.java

@@ -1,3 +1,20 @@
+//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
+//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 org.apache.cloudstack.backup;
 
 import org.apache.cloudstack.api.InternalIdentity;