Add ASF license header to findbugs-exclude-global.xml

Author: zhtttylz

dev-support/findbugs-exclude-global.xml

@@ -1,4 +1,17 @@
 <?xml version="1.0" encoding="UTF-8"?>
+<!--
+ 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. See accompanying LICENSE file.
+-->
 <FindBugsFilter>
     <Match>
         <Bug pattern="AT_NONATOMIC_64BIT_PRIMITIVE,