check both sdkLS and resLS sslpolicy for nil

[oliviassss]

Issue

#3185

Description

Check both sdkLS and resLS sslpolicy for nil when updating extra certificates for listeners. This PR fixes the edge case that when adding ssl certs to an existing service that has no ssl cert originally, the controller will not skip adding extra certs because of the sslpolicy is nil in sdkLS.

Tests

• Created a NLB with no ssl cert specified, then added multiple certs via annotation service.beta.kubernetes.io/aws-load-balancer-ssl-cert, verified all the certs got added to the listeners of the NLB successfully
• Created a ALB with no ssl cert specified, then added multiple certs via annotation alb.ingress.kubernetes.io/certificate-arn, verified all the certs got added to the listeners of the ALB successfully

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 🌟

[codecov-commenter]

Codecov Report

Patch and project coverage have no change.

Comparison is base (ff8c13d) 55.05% compared to head (841f97b) 55.05%.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #3196   +/-   ##
=======================================
  Coverage   55.05%   55.05%           
=======================================
  Files         148      148           
  Lines        8532     8532           
=======================================
  Hits         4697     4697           
  Misses       3505     3505           
  Partials      330      330           

Impacted Files	Coverage Δ
pkg/deploy/elbv2/listener_manager.go	1.08% <0.00%> (ø)

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[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

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

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[kishorj]

/lgtm