Sonartype report is wrong on new PRs

For this PR https://github.com/googleapis/google-cloud-java/pull/13853, there are a few unit tests but Soartype reported that there are [0 coverage](https://github.com/googleapis/google-cloud-java/pull/13853/checks?check_run_id=90382722071) for it.

Start with pull request 13853 and its linked check run to compare the unit tests present with the reported zero coverage. Trace how the report is produced from the pull request checks and identify why those tests are omitted. Done means the report reflects the coverage from the tests in the pull request.

Written by the indexing model from the issue text.