Rename network prefix

[jichenjc]

cloud provider and others might create this kind of resource
as well, we might consider to make it clusterapi specific

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[sbueringer]

@jichenjc Are they really creating additional networks?

[jichenjc]

they use k8s a lot, my assumption is to either make it clear created by clusterapi, or we make it configurable for resources created by us to avoid consume people ...anyway, just my own thought

[sbueringer]

It's fine for me. Just wanted to ask :). In the current state of the ClusterAPI provider I don't really care about changes like this. After a release this would be a breaking change :)

/lgtm