[release-1.20] fix sub-second precision metric reporting

[knative-prow-robot]

This is an automated cherry-pick of #16358

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 80.05%. Comparing base (00d08e7) to head (a8eb64d).
⚠️ Report is 1 commits behind head on release-1.20.

Additional details and impacted files

@@               Coverage Diff                @@
##           release-1.20   #16359      +/-   ##
================================================
+ Coverage         80.03%   80.05%   +0.02%     
================================================
  Files               214      214              
  Lines             13318    13318              
================================================
+ Hits              10659    10662       +3     
+ Misses             2301     2298       -3     
  Partials            358      358              

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

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[dprotaso]

/lgtm
/approve

[knative-prow]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: dprotaso, knative-prow-robot

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Details

Needs approval from an approver in each of these files:

• OWNERS [dprotaso]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment