Send service check as metric

[zippolyte]

What does this PR do?

Send the service check as a metric as well: 1 for up status, 0 for others

Motivation

FR

Review checklist

• PR has a meaningful title or PR has the no-changelog label attached
• Feature or bugfix has tests
• Git history is clean
• If PR impacts documentation, docs team has been notified or an issue has been opened on the documentation repo

Additional Notes

Also 🔥 some ruby leftovers

[nmuesch]

Looks good to me thanks! Can you add the new metric to the metadata.csv file?

[codecov-io]

Codecov Report

Merging #2509 into master will decrease coverage by 8.26%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master    #2509      +/-   ##
==========================================
- Coverage   84.57%   76.31%   -8.27%     
==========================================
  Files         631        4     -627     
  Lines       35398      114   -35284     
  Branches     4302        9    -4293     
==========================================
- Hits        29939       87   -29852     
+ Misses       4168       22    -4146     
+ Partials     1291        5    -1286