Automatic merge from submit-queue (batch tested with PRs 40574, 40806, 40308, 40771, 39440)
kubeadm: kube-proxy needs to know the pod subnet CIDR
**What this PR does / why we need it**: `kube-proxy` 1.5 has a new flag `cluster-cidr` that isn't specified by `kubeadm`, thus resulting in bug https://github.com/kubernetes/kubeadm/issues/102.
**Which issue this PR fixes**: fixes https://github.com/kubernetes/kubeadm/issues/102
**Special notes for your reviewer**:
/cc @luxas @dmmcquay
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