networkInterface can be empty

Sometimes you get data like this:

```
{
  vin: 'LRWYxxx',
  connectionId: 'b410afc0-8067-4248-axxx-xxxxxx',
  status: 'CONNECTED',
  createdAt: '2026-03-18T18:13:22.814654164Z',
  networkInterface: ''
}
```

Would expect this to always be wifi or cellular.