Automatic merge from submit-queue (batch tested with PRs 43951, 43386)
Move & export ConstructPodPortMapping
ConstructPodPortMapping: move & export
Move ConstructPodPortMapping to pkg/kubelet/network/hostport and export
it so downstream projects (such as OpenShift) can use it.
cc @sttts @kubernetes/sig-node-pr-reviews @kubernetes/sig-network-pr-reviews