Backport of api-gateway: stop adding all header filters to virtual host when generating xDS into release/1.16.x

[hc-github-team-consul-core]

Backport

This PR is auto-generated from #17644 to be assessed for backporting due to the inclusion of the label backport/1.16.

The below text is copied from the body of the original PR.

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Description

Header filters on http-route rules are being added to the virtual host and the route when generating xDS.
This is demonstrated by stepping through the commits in this PR:

1. The first commit demonstrates the xDS that was being generated, which includes the header modifications on both the virtual host and the routes
2. The second commit includes the fix to stop adding all header filters to the virtual host
3. The third commit updates the golden file containing the generated xDS, so this is what we're generating after the fix

Testing & Reproduction steps

• This PR adds a test verifying that this bug existed and is now fixed
• The kubernetes-sigs/gateway-api conformance tests exercise this functionality, which is how I identified this bug

Links

PR Checklist

• updated test coverage
• external facing docs updated
• appropriate backport labels added
• not a security concern

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Overview of commits

• 41a0d77 - 9e5128d - de7888a

[github-team-consul-core-pr-approver]

Auto approved Consul Bot automated PR