Validate that we can run other GWAPI implementations that are ignored by OSSM and Ingress.  We can't say we "support GWAPI" generally if we or OSSM make any changes to objects that belong to another controller.

• Verify that OSSM ignores gateways and gatewayclasses that specify some controller other than OSSM/Istio/OpenShift.  
• Verify that Ingress Controller also ignores them, e.g. plan into design for any new watchers of these objects.
• Automated tests - watch status of gateways that belong and don't belong to OpenShift, and make sure they are ignored

Stretch goals:
Check (a) that nothing updates the status of Gateway API resources that don't belong to OpenShift
(b) the ingress operator doesn't create any DNSRecord CRs or install the OSSM subscription if there aren't any gateways that OpenShift does manage
(c) OSSM doesn't create any pod or service for gateways that OpenShift doesn't manage.