feat: Add code coverage ruleset support - #4603

Thanks for your pull request! It looks like this may be your first contribution to a Google open source project. Before we can look at your pull request, you'll need to sign a Contributor License Agreement (CLA).

View this failed invocation of the CLA check for more information.

For the most up to date status, view the checks section at the bottom of the pull request.

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 98.60%. Comparing base (c674c93) to head (493645d).
⚠️ Report is 1 commits behind head on master.

@@           Coverage Diff           @@
##           master    #4603   +/-   ##
=======================================
  Coverage   98.60%   98.60%           
=======================================
  Files         198      198           
  Lines       18538    18552   +14     
=======================================
+ Hits        18279    18294   +15     
+ Misses        259      258    -1     

☔ View full report in Codecov by Harness.
📢 Have feedback on the report? Share it here.

Thank you, @stevehipwell!
Merging.