Backport of docs: K8s secondary DC requirements into release/1.12.x

[hc-github-team-consul-core]

Backport

This PR is auto-generated from #18280 to be assessed for backporting due to the inclusion of the label backport/1.12.

🚨

Warning automatic cherry-pick of commits failed. If the first commit failed,
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The person who merged in the original PR is:
@trujillo-adam
This person should manually cherry-pick the original PR into a new backport PR,
and close this one when the manual backport PR is merged in.

merge conflict error: POST https://api.github.com/repos/hashicorp/consul/merges: 409 Merge conflict []

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

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Description

This PR responds to a request to highlight the Kubernetes WAN Federation requirement that when ACLs are enabled, the Kube API of the secondary datacenters must be routable from the primary datacenter.

Links

• JIRA Ticket
• Slack convo

PR Checklist

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

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Overview of commits

• 317585c - 7ca2a56 - e46f988

[hashicorp-cla]

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2 out of 3 committers have signed the CLA.

• boruszak
• trujillo-adam
• temp

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

Auto approved Consul Bot automated PR

[github-actions]

This pull request has been automatically flagged for inactivity because it has not been acted upon in the last 60 days. It will be closed if no new activity occurs in the next 30 days. Please feel free to re-open to resurrect the change if you feel this has happened by mistake. Thank you for your contributions.

[github-actions]

Closing due to inactivity. If you feel this was a mistake or you wish to re-open at any time in the future, please leave a comment and it will be re-surfaced for the maintainers to review.