Added Apache v2 license boilerplate to listings.

docs/style/DOXYGEN.adoc

@@ -44,6 +44,18 @@ Python, Perl, and shell are shown in Listing 1 and Listing 2 below.
 ----
 /*
  *    Copyright (c) <Create year>[-<Last modified year>] Project CHIP 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
+ *
+ *    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. 
  */
 
 /**
@@ -62,6 +74,18 @@ Objective C, and Objective C{plusplus}..
 #
 #    Copyright (c) <Create year>[-<Last modified year>] Project CHIP 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
+#
+#    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.
+#
 
 ##
 #    @file