Kubeadm setup of kube-controller-manager and kube-scheduler is
lacking the --port=0 option which caused the component to enable
the insecure port by default and serve insecurely on the default
node interface.
Add --port=0 by default to both components. Users are still allowed
the explicitly set the flag (via extraArgs), which allows them
to override this default kubeadm behavior and enable the insecure port.
NOTE: the flag is deprecated and should be removed from kubeadm manifests
once it's removed from core.
f66513d98a