Bug 1868444

+++ This bug was initially created as a clone of Bug #1868078 +++

Description of problem:
When trying to enable hybrid overlay at cluster deployment time using a custom manifest degrades CNO and prevents the cluster from being deployed




Version-Release number of selected component (if applicable):


How reproducible:

create the cluster-network-03-config.yml
```apiVersion: operator.openshift.io/v1
kind: Network
metadata:
  creationTimestamp: null
  name: cluster
spec:
  clusterNetwork:
  - cidr: 192.168.0.0/16 
    hostPrefix: 23
  externalIP:
    policy: {}
  networkType: OVNKubernetes
  serviceNetwork:
  - 198.223.0.0/16
  defaultNetwork:
    type: OVNKubernetes
    ovnKubernetesConfig:
      mtu: 8500     
      hybridOverlayConfig: 
        hybridClusterNetwork: [] ```


copy to <CLUSTER-NAME>/manifests

run the installer


Steps to Reproduce:
1.
2.
3.

Actual results:
```Aug 11 14:50:14 master-0 hyperkube[2992]: E0811 14:50:14.532683    2992 kubelet.go:2194] Container runtime network not ready: NetworkReady=false reason:NetworkPluginNotReady message:Network plugin returns error: No CNI configuration file in /etc/kubernetes/cni/net.d/. Has your network provider started?
Aug 11 14:50:19 master-0 hyperkube[2992]: E0811 14:50:19.533203    2992 kubelet.go:2194] Container runtime network not ready: NetworkReady=false reason:NetworkPluginNotReady message:Network plugin returns error: No CNI configuration file in /etc/kubernetes/cni/net.d/. Has your network provider started?```


```apiVersion: operator.openshift.io/v1
kind: Network
metadata:
  creationTimestamp: "2020-08-11T14:23:27Z"
  generation: 2
  name: cluster
  resourceVersion: "3779"
  selfLink: /apis/operator.openshift.io/v1/networks/cluster
  uid: f67aded8-9b14-4c81-bee2-23e7a7cf1cb5
spec:
  clusterNetwork:
  - cidr: 172.10.0.0/16
    hostPrefix: 23
  defaultNetwork:
    ovnKubernetesConfig:
      hybridOverlayConfig:
        hybridClusterNetwork: []
      mtu: 8500
    type: OVNKubernetes
  logLevel: ""
  serviceNetwork:
  - 172.30.0.0/16
status: {}```




Expected results:


Additional info:

we tried different variations on the custom manifest...with the following results

```[@bastion ~]$ cat cluster-network-03-config.yml
apiVersion: operator.openshift.io/v1
kind: Network
metadata:
  creationTimestamp: null
  name: cluster
spec:
  clusterNetwork:
  - cidr: 192.168.0.0/16 
    hostPrefix: 23
  externalIP:
    policy: {}
  networkType: OVNKubernetes
  serviceNetwork:
  - 198.223.0.0/16
  defaultNetwork:
    type: OVNKubernetes
    ovnKubernetesConfig:
      mtu: 8500     
      hybridOverlayConfig: 
        OVNHybridOverlayEnable: true```

RESULT: 
```[root@worker-107 ~]# oc get co
NAME               VERSION   AVAILABLE   PROGRESSING   DEGRADED   SINCE
cloud-credential             True        False         False      22m
network                                                True       
[root@worker-107 ~]# oc describe co network
Name:         network
Namespace:    
Labels:       <none>
Annotations:  <none>
API Version:  config.openshift.io/v1
Kind:         ClusterOperator
Metadata:
  Creation Timestamp:  2020-08-11T14:08:26Z
  Generation:          1
  Resource Version:    3754
  Self Link:           /apis/config.openshift.io/v1/clusteroperators/network
  UID:                 cc74f0d5-820e-4b5c-af71-36f7b3ffcba4
Spec:
Status:
  Conditions:
    Last Transition Time:  2020-08-11T14:08:26Z
    Message:               Error while trying to update operator configuration: could not update object (operator.openshift.io/v1, Kind=Network) /cluster: Network.operator.openshift.io "cluster" is invalid: spec.defaultNetwork.ovnKubernetesConfig.hybridOverlayConfig.hybridClusterNetwork: Invalid value: "null": spec.defaultNetwork.ovnKubernetesConfig.hybridOverlayConfig.hybridClusterNetwork in body must be of type array: "null"
    Reason:                ApplyOperatorConfig
    Status:                True
    Type:                  Degraded
    Last Transition Time:  2020-08-11T14:08:26Z
    Status:                True
    Type:                  Upgradeable
  Extension:               <nil>
Events:                    <none>
[root@worker-107 ~]#```