revert grpc header (#11035)

* revert grpc header

* revert grpc header

* fix checkstyle

* fix checkstyle
diff --git a/dubbo-common/src/main/java/org/apache/dubbo/common/threadpool/serial/SerializingExecutor.java b/dubbo-common/src/main/java/org/apache/dubbo/common/threadpool/serial/SerializingExecutor.java
index 041ba56..9fde0f9 100644
--- a/dubbo-common/src/main/java/org/apache/dubbo/common/threadpool/serial/SerializingExecutor.java
+++ b/dubbo-common/src/main/java/org/apache/dubbo/common/threadpool/serial/SerializingExecutor.java
@@ -1,10 +1,9 @@
 /*
- * 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
+ * Copyright 2014 The gRPC Authors
+ *
+ * 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
  *
diff --git a/pom.xml b/pom.xml
index 6546479..2d9a2e3 100644
--- a/pom.xml
+++ b/pom.xml
@@ -315,6 +315,7 @@
                                     <skip>${checkstyle.skip}</skip>
                                     <excludes>
                                         **/JSONWriter.java,
+                                        **/org/apache/dubbo/common/threadpool/serial/SerializingExecutor.java,
                                         **/org/apache/dubbo/common/threadlocal/InternalThreadLocal.java,
                                         **/org/apache/dubbo/common/threadlocal/InternalThreadLocalMap.java,
                                         **/org/apache/dubbo/common/timer/TimerTask.java,
@@ -680,6 +681,8 @@
                         <exclude>Jenkinsfile</exclude>
                         <exclude>**/codestyle/*</exclude>
                         <exclude>**/resources/META-INF/**</exclude>
+                        <!-- exclude the grpc files -->
+                        <exclude>**/org/apache/dubbo/common/threadpool/serial/SerializingExecutor.java</exclude>
                         <!-- exclude the netty files -->
                         <exclude>**/org/apache/dubbo/common/threadlocal/InternalThreadLocal.java</exclude>
                         <exclude>**/org/apache/dubbo/common/threadlocal/InternalThreadLocalMap.java</exclude>