build(PMD): renamed rules.xml -> custom-rules.xml

Author: boolivar

gradle/config/pmd/rules.xml renamed to gradle/config/pmd/custom-rules.xml

@@ -73,6 +73,6 @@
     <rule ref="category/java/performance.xml">
     </rule>
 
-    <rule ref="rules.xml/StaticStarImports"/>
-    <rule ref="rules.xml/UseContextClassLoader"/>
+    <rule ref="custom-rules.xml/StaticStarImports"/>
+    <rule ref="custom-rules.xml/UseContextClassLoader"/>
 </ruleset>