Add support for Keycloak 24/re-encrypt Route

[pgodowski]

What this PR does / why we need it:

In Keycloak 24, when it is behind re-encrypt Route, any incoming http requests fail with http/500, with NPE exception saying http Host header is missing. Seems the fix is to add the proxy headers setting to parse x-forwarded http header.

Which issue(s) this PR fixes:
Fixes https://github.ibm.com/IBMPrivateCloud/roadmap/issues/65100 and keycloak/keycloak#33988

Special notes for your reviewer:

1. How the test is done?

Do fresh deploy of Keycloak 24 on ROSA cluster. Check Route keycloak created works fine and renders Keycloak Admin UI

[ibm-ci-bot]

Hi @pgodowski. Thanks for your PR.

I'm waiting for a IBM member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

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[Daniel-Fan]

/lgtm

[ibm-ci-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: Daniel-Fan, pgodowski

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