Allow tweaking host network setting independently of the Service type

[MOZGIII]

Sometimes you want the ClusterIP with the host network, or NodePort without the host network (like in our case). These settings should not be coupled together.

[loganintech]

Seconded, I use NodePort and do not want host networking. I manually edited the chart for now, but this was a surprising and frustrating thing to debug. My use-case is running two servers side-by-side for different groups of people. Since the container uses host networking the second container would not launch because there is no free port.