runtimes may return an arbitrary number of Pod IPs, however, kubernetes
only takes into consideration the first one of each IP family.
The order of the IPs are the one defined by the Kubelet:
- default prefer IPv4
- if NodeIPs are defined, matching the first nodeIP family
PodIP is always the first IP of PodIPs.
The downward API must expose the same IPs and in the same order than
the pod.Status API object.