Add license header

spotbugs-exclude.xml

@@ -1,3 +1,22 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+  ~ Copyright (c) 2023, WSO2 LLc. (http://www.wso2.org) All Rights Reserved.
+  ~
+  ~ WSO2 Inc. 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.
+  -->
+
 <FindBugsFilter>
     <!-- false-positive. See details at https://github.com/spotbugs/spotbugs/issues/1601 -->