Replace explicit service configuration with roles
What does this MR do?
Reworks the ha postgres documentation to use the roles introduced into gitlab-omnibus by omnibus-gitlab!2134 (merged)
Are there points in the code the reviewer needs to double check?
- That omnibus-gitlab!2134 (merged) is merged/released
- That the roles introduced in that MR match those used in this one
Why was this MR needed?
Screenshots (if relevant)
Does this MR meet the acceptance criteria?
- Changelog entry added, if necessary
- Documentation created/updated
- API support added
- Tests added for this feature/bug
- Has been reviewed by UX
- Has been reviewed by Frontend
- Has been reviewed by Backend
- Has been reviewed by Database
- Conform by the merge request performance guides
- Conform by the style guides
- Squashed related commits together
- Internationalization required/considered
- If paid feature, have we considered GitLab.com plan and how it works for groups and is there a design for promoting it to users who aren't on the correct plan