Ensure database.yml and secrets.yml updates for CI in 8.0
When a user upgrades from version prior to 7.13, the changes in database.yml and secrets.yml are not propagated to 8.0 because we are no longer updating ci credentials.
Related issue gitlab-org/gitlab-ce#2843
- Make sure that host field in database.yml of CI has correct value, default `/var/opt/gitlab/postgresql
- Make sure secrets.yml for CI exists with generated db_key_base