Add a separate example for dualstack ALB

[kishorj]

Issue

Add a separate example for dualstack ALB configuration.

Description

The alb.ingress.kubernetes.io/ip-address-type: dualstack annotation on an ingress requires subnets with IPv6 configuration. So add a separate example to limit the effect to ipv4 only users.

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
• 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 🌟

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: kishorj

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• OWNERS [kishorj]

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[codecov-commenter]

Codecov Report

Merging #2445 (044d658) into main (46668f1) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##             main    #2445   +/-   ##
=======================================
  Coverage   53.37%   53.37%           
=======================================
  Files         140      140           
  Lines        7966     7966           
=======================================
  Hits         4252     4252           
  Misses       3397     3397           
  Partials      317      317           

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[johngmyers]

Filed kubernetes/kubernetes#107392 to add IPv6 support to echoserver.

[johngmyers]

/lgtm