[BASTION] Unable to reference VNET in a different resource group

I am attempting to create a Bastion Host using an existing VNET. Instead of using the Name of the VNET, I tried to use the ID of the VNET and the ID of Bastion Subnet for the VNET Name.

CLI Version
2.21.0 (can't download 2.22.0 yet)

Command

```bash
az network bastion create \
--name BASTION_NAME \
--public-ip-address PUBLIC_IP_ADDRESS
--resource-group RESOURCE_GROUP
--vnet-name /subscriptions/XXXXX/resourceGroups/VNET_RESOURCE_GROUP/providers/Microsoft.Network/virtualNetworks/VNET_NAME/subnets/AzureBastionSubnet \
--location LOCATION
```

Error:

```json
"error": {
"code": "InvalidRequestFormat",
"message": "Cannot parse the request.",
"details": [
{
"code": "InvalidJsonReferenceFormat",
"message": "Reference Id /subscriptions/XXXXX/resourceGroups/RESOURCE_GROUP/providers/Microsoft.Network/virtualNetworks//subscriptions/XXXXX/resourceGroups/VNET_RESOURCE_GROUP/providers/Microsoft.Network/virtualNetworks/VNET_NAME/subnets/AzureBastionSubnet is not formatted correctly. The Id is expected to reference resources of type virtualNetworks/subnets. Path properties.ipConfigurations[0].properties.subnet."
}
]
}
```
It seems that the Subnet ID is being appended as the VNET name.