Install gitlab-metrics-exporter into CNG images
We can already install the exporter via a Rake task added in gitlab#358025 (closed).
However, for it to be available to production services (and similar environments like review apps), we also need to compile and install it into CNG containers.
- Requirement for: gitlab#355449 (closed)
- Similar to: omnibus-gitlab#6713 (closed)
Edited by Matthias Käppler