Configure profile with persistent Elasticsearch storage

While testing I wanted to retain some data stored in Elasticsearch (for example to avoid running `metricbeat setup` at each restart).

This could be achieved by adding a volume to `elasticsearch` service. I don't think is necessary to bind mount it to a local folder, having a volume already guarantees persistency.

I would like to have this under a CLI flag when creating a profile (i.e. `--persistent`).