feat: add custom topologySpreadConstraints support to coredns

[thiagoluiznunes]

Context on the change

Recently at WildlifeStudios, we had a short temporary outage in CoreDNS in one of our clusters, since a single node crashed, and all CoreDNS pods were running on it.

So, to avoid that, we would like to set our own topologySpreadContraints parameters according to our user case.

What does this PR do?

This PR adds support for customizing the field topologySpreadConstraints in the template of the CoreDNS add-on.

[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: thiagoluiznunes / name: Thiago Luiz (5158908, 824192b)

[k8s-ci-robot]

Hi @thiagoluiznunes. Thanks for your PR.

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[hakman]

/ok-to-test

[k8s-ci-robot]

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[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by:
Once this PR has been reviewed and has the lgtm label, please assign zetaab for approval. For more information see the Kubernetes Code Review Process.

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

Needs approval from an approver in each of these files:

• OWNERS

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

[thiagoluiznunes]

Hey folks, could you review the PR?
cc @hakman @justinsb

[hakman]

@justinsb Could you please take a look?
/lgtm
/assign @justinsb