Use NLB as default SLB provider

[xuanyunhui]

What would you like to be added:

Use NLB as default SLB provider

Why is this needed:

CLB is old SLB product in Alicloud， Instead NLB for layer 4 and ALB for layer 7 is better，so I think make NLB is default for layer 4 load-balancing is good choice.

[k8s-triage-robot]

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This bot triages un-triaged issues according to the following rules:

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/lifecycle stale

[k8s-triage-robot]

The Kubernetes project currently lacks enough active contributors to adequately respond to all issues.

This bot triages un-triaged issues according to the following rules:

• After 90d of inactivity, lifecycle/stale is applied
• After 30d of inactivity since lifecycle/stale was applied, lifecycle/rotten is applied
• After 30d of inactivity since lifecycle/rotten was applied, the issue is closed

You can:

• Mark this issue as fresh with /remove-lifecycle rotten
• Close this issue with /close
• Offer to help out with Issue Triage

Please send feedback to sig-contributor-experience at kubernetes/community.

/lifecycle rotten