Support multiple private dns zone configuration when updating private DNS Zones through Azure Policy

[SenthuranSivananthan]

Is your feature request related to a problem? Please describe.
There are some Azure PaaS services that have multiple DNS Zone configuration and they must be configured together. An example is Azure Machine Learning Service which has two DNS zones (privatelink.notebooks.azure.net and privatelink.api.azureml.ms) that must be added as a set. Failure to add them as a set means only the last DNS zone configuration is kept.

This is an example for Azure ML Private DNS Zone group configuration. See section privateDnsZoneConfigs

        {
            "type": "Microsoft.Network/privateEndpoints/privateDnsZoneGroups",
            "apiVersion": "2020-11-01",
            "name": "[concat(parameters('privateEndpoints_amlzru2t6o5pygbi_endpoint_name'), '/default')]",
            "dependsOn": [
                "[resourceId('Microsoft.Network/privateEndpoints', parameters('privateEndpoints_amlzru2t6o5pygbi_endpoint_name'))]"
            ],
            "properties": {
                "privateDnsZoneConfigs": [
                    {
                        "name": "[parameters('privateDnsZones_privatelink_api_azureml_ms_externalid')]",
                        "properties": {
                            "privateDnsZoneId": "[parameters('privateDnsZones_privatelink_api_azureml_ms_externalid_1')]"
                        }
                    },
                    {
                        "name": "privatelink_notebooks_azure_net",
                        "properties": {
                            "privateDnsZoneId": "[parameters('privateDnsZones_privatelink_notebooks_azure_net_externalid')]"
                        }
                    }
                ]
            }
        }

Describe the solution you'd like
Update the existing deployIfNotExists policies so that an array of DNS zones can be set.