Add Grafana reporting option

What does this MR do?

The Grafana reporting was supposed to stay enabled by default as part of our integration. Adding an option to opt-out is what we want.

• Re-enable Grafana reporting ping by default with option to opt-out.
• Disable Grafana reporting when the GitLab usage ping is disabled.
• Add a GitLab-Omnibus reporting tag to identify the embedded distribution.

Related issues

#4832 (closed)

Checklist

See Definition of done.

For anything in this list which will not be completed, please provide a reason in the MR discussion

Required

• Merge Request Title, and Description are up to date, accurate, and descriptive
• MR targeting the appropriate branch
• MR has a green pipeline on GitLab.com
• Pipeline is green on dev.gitlab.org if the change is touching anything besides documentation or internal cookbooks
• trigger-package has a green pipeline running against latest commit

Expected (please provide an explanation if not completing)

• Test plan indicating conditions for success has been posted and passes
• Documentation created/updated
• Tests added
• Integration tests added to GitLab QA
• Equivalent MR/issue for the GitLab Chart opened