So far, on ContainerStart, the daemon was silently backfilling empty
PortBindings slices with a PortBinding with unspecified HostIP and
HostPort. This was done by github.com/docker/go-connections/nat.SortPortMap.
This backfilling doesn't make much sense, and we're trying to remove
that package. So, move the backfilling to the API server, keep it for
older API versions, deprecate it for API 1.52, and drop it for API 1.53
and above.
Signed-off-by: Albin Kerouanton <albinker@gmail.com>