Fix the example for the device-roaming POST REQUEST

[bigludo7]

Problem description
Very small one
We should fix the example for the device-roaming POST REQUEST as we have:

  "device": {
    "phoneNumber": "+123456789",
    "networkAccessIdentifier": "123456789@domain.com",
    "ipv4Address": {
      "publicAddress": "84.125.93.10",
      "publicPort": 59765
    },
    "ipv6Address": "2001:db8:85a3:8d3:1319:8a2e:370:7344"
  }
}

We should have instead 5 valid examples using one of the identifier or none identifier.

WDYT?

Expected action

Additional context