Clear the externalIP when Service type changes from LoadBalancer to something else

[MOZGIII]

Currently, when the Serivce type changes from LoadBalancer to something else the externalIP that we assigned previously remains. It should be cleared out, but we don't want to touch the externalIPs that weren't set by us - so we need to somehow mark that the externalIP was assigned by us so that we can later check the marker and clear both the marker itself and the externalIP field.