vcsim: Add UpdateNetworkConfig to HostNetworkSystem
vcsim: Add UpdateNetworkConfig to HostNetworkSystem

bruceadowns/govmomi,bruceadowns/govmomi,dougm/govmomi,vmware/govmomi,vmware/govmomi,dougm/govmomi,dougm/govmomi,bruceadowns/govmomi,vmware/govmomi