Add cel tests for upstreamsettingspolicy

[sarthyparty]

Proposed changes

Problem: There were no CEL tests for UpstreamSettingsPolicy

Solution: I added it

Testing: Describe any testing that you did.
Closes #3672

Checklist

Before creating a PR, run through this checklist and mark each as complete.

• I have read the CONTRIBUTING doc
• I have added tests that prove my fix is effective or that my feature works
• I have checked that all unit tests pass after adding my changes
• I have updated necessary documentation
• I have rebased my branch onto main
• I will ensure my PR is targeting the main branch and pulling from my branch from my own fork

Release notes

If this PR introduces a change that affects users and needs to be mentioned in the release notes,
please add a brief note that summarizes the change.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 86.87%. Comparing base (e0607ee) to head (1e2b0f1).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3742      +/-   ##
==========================================
- Coverage   86.90%   86.87%   -0.04%     
==========================================
  Files         128      128              
  Lines       16201    16201              
  Branches       62       62              
==========================================
- Hits        14079    14074       -5     
- Misses       1949     1954       +5     
  Partials      173      173              

☔ 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.
• 📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.

[shaun-nx]

Looks great to me. Great job @sarthyparty! 🎉

[salonichf5]

🚀