KEP-2436 PRR: Controller Manager Leader Migration to alpha

[jiahuif]

This PR update KEP #2436 as a new feature going alpha in 1.21 milestone.

[jiahuif]

/assign @deads2k
For production readiness review of nothing to alpha stage

[deads2k]

PRR looks good for alpha. thanks.

/approve

[jiahuif]

Thank you for PRR.

/assign @cheftako

for sig-cloudprovider

[k8s-ci-robot]

@jiahuif: GitHub didn't allow me to assign the following users: for, sig-cloudprovider.

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In response to this:

Thank you for PRR.

/assign @cheftako for sig-cloudprovider

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[cheftako]

/lgtm
/approve

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: cheftako, deads2k, jiahuif

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• keps/prod-readiness/OWNERS [deads2k]
• keps/sig-cloud-provider/OWNERS [cheftako]

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