Escape newlines and " in metadata script.
Escape newlines and " in metadata script.

Change-Id: If0c8667042fe9f630ac04f1ca5c7f390fdcbc94a
Reviewed-on: https://review.openstack.org/34058
Reviewed-by: Jeremy Stanley <98883b97e35b7bb1ac282bb863f2e9d917db0454@yuggoth.org>
Reviewed-by: Clark Boylan <635fc31d01fa593720982fa0568e87170cedbe2c@gmail.com>
Approved: Jeremy Stanley <98883b97e35b7bb1ac282bb863f2e9d917db0454@yuggoth.org>
Tested-by: Jenkins

open-switch/infra_puppet-jenkins,open-switch/infra_puppet-jenkins