Put some order on os-refresh-config systemd

cloud-init is populating the file /var/lib/cloud/data/cfn-init-data
with metadata and needs to happen before os-refresh-config is run
which in turn needs to happen before the cfn-hup cronjob.

Change-Id: I07fc60c4a165a42eeae1a8e5a20609a6e17fd790