When using the 0.10 serving operator, I've run into issues where after bringing up serving via the CR and trying to deploy a ksvc, the ksvc never comes up. The Revision stays at ready status=Unknown, reason=Deploying.

It appears that the reason that the revision isn't coming up is because the webhook isn't configured properly. After coming up, serving (the webhook controller, I believe) writes necessary configuration to the MutatingWebhookConfiguration webhook.serving.knative.dev in the top level webhooks key. Shortly after writing the configuration, the operator reconcile loop re-applies it's own configuration for this object, wiping out the configuration needed by the webhook controller. When watching the MutatingWebhookConfiguration, I do see it eventually get fixed up after some period of time, but my revision still doesn't come up automatically. However, once the MutatingWebhookConfiguration gets into the correct state, I can deploy services successfully.

I did verify that if I update the operator to not touch existing resources (create them only), that I am able to bring up a ksvc as expected. This obviously ins't a long-term solution, but does seem to indicate we may need to be more selective about what or how the operator updates serving resources.

This relates to #163