Acceptance criteria:

Istio Operator logs warning when deprecated fields are set:

spec: 
  security: 
      certificateAuthority: 
        cert-manager: 
          pilotSecretName: istiod-tls
          rootCAConfigMapName: istio-ca-root-cert

This check should be performed in this function: https://github.com/maistra/istio-operator/blob/maistra-2.4/pkg/controller/versions/strategy_v2_4.go#L276, and if the deprecated fields exist, a warning should be returned.