Enhancing the PostgreSQLXARecoveryWithNFSDisconnectLoadTest with adding a test which disconnects a pod only from the openshift api

I would be good to add some more OpenShift network crash tests up to the one PostgreSQLXARecoveryWithNFSDisconnectLoadTest#testScaleDownToTwo. The idea is to have a test which disconnect only OpenShift API from the pod while the pod is still able to communicate with NFS and client (the test) is capable to sending requests to the pod.