[feat gw-api]add conformance test setup

[shuqz]

Description

set up instruction for conformance test reproduce.

Checklist

• Added tests that cover your change (if possible)
• Added/modified documentation as required (such as the README.md, or the docs directory)
• Manually tested
  manually run single test case to test if timeout config and default target type is working, and test passed
• Made sure the title of the PR is a good description that can go into the release notes

BONUS POINTS checklist: complete for good vibes and maybe prizes?! 🤯

• Backfilled missing tests for code in same general area 🎉
• Refactored something and made the world a better place 🌟

[shuqz]

/retest

[zac-nixon]

/lgtm

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: shuqz, zac-nixon

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[shraddhabang]

/lgtm