serenity xml file is not created when executed with gradle

Question

Can anyone tell me why the serenity xml file is not getting generated when executed script with gradle.

html files, SERENITY-JUNIT.xml, index.html is getting created but .xml file is not getting created.

build.gradle

repositories {    
jcenter()
mavenCentral()
}

buildscript {
repositories {
mavenLocal()
jcenter {
url "http://jcenter.bintray.com/"
}
}

dependencies {
classpath("net.serenity-bdd:serenity-gradle-plugin:1.2.2-rc.5")
}
}

apply plugin: 'java'
apply plugin: 'eclipse'
apply plugin: 'idea'
apply plugin: 'net.serenity-bdd.aggregator' 

jar {
baseName = 'gs-gradle'
version =  '0.0.1'
}

dependencies {
    compile 'org.seleniumhq.selenium:selenium-java:3.0.1'
    compile 'net.serenity-bdd:serenity-junit:1.2.2-rc.5'
    compile 'net.serenity-bdd:serenity-core:1.2.2-rc.5'
    compile 'net.serenity-bdd:serenity-jbehave:1.19.0'
    compile 'net.serenity-bdd:serenity-gradle-plugin:1.2.2-rc.5'
    compile 'org.slf4j:slf4j-simple:1.7.22'
    compile 'log4j:log4j:1.2.17'
    testCompile 'junit:junit:4.12'
    compile 'com.itextpdf:itextpdf:5.5.10'
    compile 'com.itextpdf.tool:xmlworker:5.5.10'
    compile 'commons-io:commons-io:2.5'
    compile 'org.assertj:assertj-core:3.6.1'
    compile 'com.googlecode.lambdaj:lambdaj:2.3.3'
    compile 'org.scream3r:jssc:2.8.0'
    compile 'org.apache.commons:commons-exec:1.3'
    compile 'org.apache.commons:commons-lang3:3.5'
    compile 'com.jcraft:jsch:0.1.54'
    compile 'com.googlecode.json-simple:json-simple:1.1.1'
 }

task testAudioAlarm(type: Test)
{ 
description 'Runs the Alarm recording BDD tests.' 
scanForTestClasses = false 
maxParallelForks = 1 
forkEvery = 1 
include '**/AMSTestSuite' 
}

gradle.startParameter.continueOnFailure = true

command i used to execute script "gradle clean test aggregate"