Add DnsOption Flag to allow user to have customized resolve.conf

[weiling61]

What this PR does / why we need it: DnsOption needs to be entered by users according to their super cluster environment. Add flag to allow user to config DNSOptions

Which issue(s) this PR fixes (optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close the issue(s) when PR gets merged): Fixes # N/A

[linux-foundation-easycla[bot]]

The committers listed above are authorized under a signed CLA.

• :white_check_mark: login: weiling61 / name: Wei Ling (fa7b9e8dc767c749dbebb65b76066cb222fc5b9e, 6e153131e592ad757af4a51ae31461b444c81196, d29ef8a6ba8abc6ead4e373a44f41c0493db96cd, a22345f49463e0fec816d451c0bd87b3a35673e8, 75f5f862a63c20dfa06598cc2a32a4ddc82121ed)

[weiling61]

@christopherhein

[weiling61]

/retest

[weiling61]

provider-nest-test seems not working properly

[christopherhein]

provider-nest-test seems not working properly

Did you check out what it says here - https://prow.k8s.io/view/gs/kubernetes-jenkins/pr-logs/pull/kubernetes-sigs_cluster-api-provider-nested/261/pull-cluster-api-provider-nested-test/1506859629164892160

[weiling61]

@christopherhein I checked test log, the file was not related to my change at all. Please check https://github.com/kubernetes-sigs/cluster-api-provider-nested/pull/264, this simple testing PR was also failed.

[weiling61]

/retest

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: christopherhein, weiling61

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Needs approval from an approver in each of these files: - ~~[OWNERS](https://github.com/kubernetes-sigs/cluster-api-provider-nested/blob/main/OWNERS)~~ [christopherhein] Approvers can indicate their approval by writing `/approve` in a comment Approvers can cancel approval by writing `/approve cancel` in a comment