Increase CoreDNS default ttl

[johanneswuerbach]

Increase the CoreDNS default ttl to be inline with kubernetes upstream kubernetes/kubernetes#76238 and the previous kube-dns ttl.

We switching from kube-dns to CoreDNS, we noticed a visible bump in coredns-nodelocal request duration and an increase in cache misses.

This change should make the switch less impactful for others.

[k8s-ci-robot]

Hi @johanneswuerbach. Thanks for your PR.

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[johanneswuerbach]

/assign @johngmyers

[hakman]

/ok-to-test

[hakman]

Thanks @johanneswuerbach. It's a nice update.
/lgtm
/approve

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: hakman, johanneswuerbach

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[hakman]

/retest