Update maven_metadata_param to make use of convert_mapping_to_xml()
Update maven_metadata_param to make use of convert_mapping_to_xml()

Change-Id: I355393cb683598f19883cb6e28de3ce1b30ec6f8

wsoula/jenkins-job-builder,rsig/jenkins-job-builder,rsig/jenkins-job-builder,dataxu/jenkins-job-builder,phinexus/jenkins-job-builder,puppetlabs/jenkins-job-builder,wsoula/jenkins-job-builder,dataxu/jenkins-job-builder,phinexus/jenkins-job-builder,gforcada/jenkins-job-builder,phinexus/jenkins-job-builder,OSSystems/jenkins-job-builder,wikimedia/integration-jenkins-job-builder,gforcada/jenkins-job-builder,phinexus/jenkins-job-builder,wikimedia/integration-jenkins-job-builder,OSSystems/jenkins-job-builder,phinexus/jenkins-job-builder,wsoula/jenkins-job-builder,wikimedia/integration-jenkins-job-builder,wikimedia/integration-jenkins-job-builder,puppetlabs/jenkins-job-builder,gforcada/jenkins-job-builder,rsig/jenkins-job-builder,dataxu/jenkins-job-builder,dataxu/jenkins-job-builder,wsoula/jenkins-job-builder,puppetlabs/jenkins-job-builder,puppetlabs/jenkins-job-builder,wikimedia/integration-jenkins-job-builder,rsig/jenkins-job-builder,OSSystems/jenkins-job-builder,gforcada/jenkins-job-builder,OSSystems/jenkins-job-builder,gforcada/jenkins-job-builder