remove RegexpHeader constrant.

config/quality/checkstyle/checkstyle-config.xml

@@ -237,10 +237,4 @@
     <property name="format" value="[ \t]+$"/>
     <property name="message" value="Trailing whitespace"/>
   </module>
-  <module name="RegexpHeader">
-    <property name="severity" value="error"/>
-    <message key="header.mismatch"
-             value="Android Copyright header seems to be incorrect. Expected ''{0}'' on this line."/>
-    <property name="header" value="^/\*\n \* Copyright \([Cc]\) [0-9]{4} The Android Open Source Project\n \*\n \* Licensed under the Apache License, Version 2\.0 \(the \&quot;License\&quot;\);\n \* you may not use this file except in compliance with the License.\n \* You may obtain a copy of the License at\n \*\n \*      http:\/\/www\.apache\.org\/licenses\/LICENSE-2\.0\n \*\n \* Unless required by applicable law or agreed to in writing, software\n \* distributed under the License is distributed on an &quot;AS IS&quot; BASIS,\n \* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied\.\n \* See the License for the specific language governing permissions and\n \* limitations under the License\.\n \*\/" />
-  </module>
 </module>
\ No newline at end of file