[CustomDomainConfiguration]: missing certificateKeyVaultProperties

### Resource Type

Microsoft.App/managedEnvironments

### Api Version

2024-03-01

### Issue Type

Missing property(s)

### Other Notes

_No response_

### Bicep Repro

```bicep
resource containerAppEnv 'Microsoft.App/managedEnvironments@2024-03-01' = {
location: location
name: serviceName
properties: {
customDomainConfiguration: {
certificateKeyVaultProperties: { // error
}
}
}
```

### Confirm

- [X] I have read the troubleshooting guide and looked for duplicates.

Start with the Microsoft.App/managedEnvironments@2024-03-01 type definition and inspect customDomainConfiguration. Confirm that certificateKeyVaultProperties is represented and that the supplied Bicep repro no longer reports an error; the issue names no specific file or test to run.

Written by the indexing model from the issue text.