NodeSelector is not being set for RuntimeClass when using MatchExpressions in KataConfigPoolSelector

[bpradipt]

Description
NodeSelector is not being set for RuntimeClass when using MatchExpressions in KataConfigPoolSelector

Steps to reproduce the issue:

1. Create KataConfig from OpenShift UI which uses matchExpressions or use the following yaml

apiVersion: kataconfiguration.openshift.io/v1
kind: KataConfig
metadata:
  name: example-kataconfig
spec:
  kataConfigPoolSelector:
     matchExpressions:
       - key: custom-kata1
         operator: In
         values:
         - "test"

Describe the results you received:

Kata runtime will be successfully installed on the nodes labelled with custom-kata1=test, however NodeSelector settings in RuntimeClass will be empty
oc get runtimeclass kata -o yaml

scheduling:
  nodeSelector: {}

Describe the results you expected:
oc get runtimeclass kata -o yaml

scheduling:
    nodeSelector:
        custom-kata1: test