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 86.88%. Comparing base (235a4b2) to head (6fa3824).

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3742      +/-   ##
==========================================
+ Coverage   86.85%   86.88%   +0.03%     
==========================================
  Files         128      128              
  Lines       16187    16187              
  Branches       62       62              
==========================================
+ Hits        14059    14064       +5     
+ Misses       1954     1950       -4     
+ Partials      174      173       -1     

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[shaun-nx]

Looks great to me. Great job @sarthyparty! 🎉

[salonichf5]

🚀