Add missing ASL header.

Author: ggregory-rocket

.github/workflows/maven.yml

@@ -1,3 +1,18 @@
+#   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
+#
+#   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.
+
 name: Java CI
 
 on: [push]