[MCHECKSTYLE-184] Allow src/main/resources to be searched by Checkstyle

Add another properties file with a different key so that there is an actual error. Otherwise the files won't show up in the report.

git-svn-id: https://svn.apache.org/repos/asf/maven/plugins/trunk@1446931 13f79535-47bb-0310-9956-ffa450edef68