From the API, we can't see the state of the snippet flag in the partition table templates and can't set that flag.

I quickly fixed it with a `sed -ie 's/attributes :layout, :locked/attributes :layout, :locked, :snippet/' /usr/share/foreman/app/views/api/v2/ptables/show.json.rabl`

I'm not enough aware of the foreman source code but I probably can generate a PR.