call subnet auto discovery when lb scheme changes

[oliviassss]

Description

Follow up with the PR 2125 and PR 2129.

Call subnet auto discovery when the LB scheme would change.

Tests:

1. Created internal NLB, changed the scheme to internet-facing, verified the controller selected public subnet for new NLB;
2. Created internet-facing NLB, changed the scheme to internal, verified the controller selected internal subnet for new NLB;
3. Created internal ALB, changed the scheme to internet-facing, verified the controller selected public subnets for new ALB;
4. Created internet-facing ALB, changed the scheme to internal, verified the controller selected internal subnets for new ALB;

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]

Hi @oliviassss. Thanks for your PR.

I'm waiting for a kubernetes-sigs 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.

Once the patch is verified, the new status will be reflected by the ok-to-test label.

I understand the commands that are listed here.

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.

[codecov-commenter]

Codecov Report

Merging #2387 (fd7219d) into main (e87a5e9) will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##             main    #2387   +/-   ##
=======================================
  Coverage   53.85%   53.86%           
=======================================
  Files         140      140           
  Lines        7843     7844    +1     
=======================================
+ Hits         4224     4225    +1     
  Misses       3302     3302           
  Partials      317      317           

Impacted Files	Coverage Δ
pkg/ingress/model_build_load_balancer.go	63.81% <100.00%> (ø)
pkg/service/model_build_load_balancer.go	82.64% <100.00%> (+0.07%)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update e87a5e9...fd7219d. Read the comment docs.

[M00nF1sh]

/lgtm
/approve

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: M00nF1sh, oliviassss

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Needs approval from an approver in each of these files:

• OWNERS [M00nF1sh]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[kishorj]

/ok-to-test

[kishorj]

/retest