Don't rely on lsb_release for hosts template write
Don't rely on lsb_release for hosts template write

This is problematic for the containerised heat-agents, lsb_release has
to be bind-mounted in, and atomic host doesn't even have lsb_release
installed.

Instead just write to every /etc/cloud/templates/hosts.*.tmpl file.

Change-Id: If2aab7e9b1e03aa657baf1c33aa4392ef7044075

openstack/tripleo-heat-templates,openstack/tripleo-heat-templates,dprince/tripleo-heat-templates,dprince/tripleo-heat-templates