Automatic merge from submit-queue (batch tested with PRs 66291, 66471, 66499). If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.

kubeadm: Pull sidecar and dnsmasq-nanny images when using kube-dns

**What this PR does / why we need it**:

It appears that sidecar and dnsmasq-nanny images are now required for
kube-dns deployment to work correctly. Thus the following default kube-dns
images are used now:

- k8s.gcr.io/k8s-dns-kube-dns-amd64:1.14.10
- k8s.gcr.io/k8s-dns-sidecar-amd64:1.14.10
- k8s.gcr.io/k8s-dns-dnsmasq-nanny-amd64:1.14.10

**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 kubernetes/kubeadm#1016

**Special notes for your reviewer**:

/cc @kubernetes/sig-cluster-lifecycle-pr-reviews
/area kubeadm
/assign @luxas
/assign @timothysc
/kind bug

**Release note**:

```release-note
kubeadm: Pull sidecar and dnsmasq-nanny images when using kube-dns
```