PMD: XML config file, enable most of unnecessary

app/build.gradle

@@ -208,16 +208,8 @@ pmd {
 }
 
 task pmd(type: Pmd, dependsOn: assembleDebug) {
-    ruleSets = [
-        //'java-basic',
-        'java-unusedcode',
-        'java-android',
-        'java-clone',
-        'java-finalizers',
-        'java-imports',
-        'java-migrating',
-        //'java-unnecessary', // too nitpicky with parenthesis
-    ]
+    ruleSetFiles = files("${project.rootDir}/config/pmd/rules.xml")
+    ruleSets = [] // otherwise defaults clash with the list in rules.xml
     source 'src/main/java', 'src/test/java', 'src/androidTest/java'
     include '**/*.java'
 }

app/src/main/java/org/fdroid/fdroid/privileged/views/CaffeinatedScrollView.java

@@ -40,6 +40,7 @@ public class CaffeinatedScrollView extends ScrollView {
     /**
      * Make this visible so we can call it
      */
+    @SuppressWarnings("PMD.UselessOverridingMethod")
     @Override
     public boolean awakenScrollBars() {
         return super.awakenScrollBars();

config/pmd/rules.xml

@@ -0,0 +1,18 @@
+<?xml version="1.0"?>
+<ruleset name="Custom ruleset"
+        xmlns="http://pmd.sf.net/ruleset/1.0.0"
+        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+        xsi:schemaLocation="http://pmd.sf.net/ruleset/1.0.0 http://pmd.sf.net/ruleset_xml_schema.xsd"
+        xsi:noNamespaceSchemaLocation="http://pmd.sf.net/ruleset_xml_schema.xsd">
+
+    <!--<rule ref="rulesets/java/basic.xml"/>-->
+    <rule ref="rulesets/java/unusedcode.xml"/>
+    <rule ref="rulesets/java/android.xml"/>
+    <rule ref="rulesets/java/clone.xml"/>
+    <rule ref="rulesets/java/finalizers.xml"/>
+    <rule ref="rulesets/java/imports.xml"/>
+    <rule ref="rulesets/java/migrating.xml"/>
+    <rule ref="rulesets/java/unnecessary.xml">
+        <exclude name="UselessParentheses"/> <!--Too nitpicky-->
+    </rule>
+</ruleset>