Conformance: update input flags

[sjberman]

Problem: The upstream conformance library updated their input validation for some flags, causing our nightly tests to fail.

Solution: Update the way we initialize these flags so that they pass.

Testing: Conformance tests on main branch now pass.

Closes #3584

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 (f8ee6d1) to head (ff09c59).

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #3624      +/-   ##
==========================================
- Coverage   86.92%   86.87%   -0.06%     
==========================================
  Files         127      127              
  Lines       15287    15287              
  Branches       62       62              
==========================================
- Hits        13288    13280       -8     
- Misses       1846     1852       +6     
- Partials      153      155       +2     

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[sjberman]

Closing, the change in Gateway API was reverted.