Enable XML reporting for JaCoCo for the Sonar Gradle plugin

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1882843 13f79535-47bb-0310-9956-ffa450edef68

build.gradle

@@ -170,6 +170,12 @@ subprojects {
         toolVersion = '0.8.6'
     }
 
+    jacocoTestReport {
+        reports {
+            xml.enabled true
+        }
+    }
+
     // ensure the build-dir exists
     projectDir.mkdirs()