"credentials.json" file is missing groups causing an NPE once using `FileBasedCredentialsModule`

[avibhstarburst]

currently -

    "identity": {
      "user": "test-username",
      "id": "xyzpdq"
    }

works -

    "identity": {
      "user": "test-username",
      "id": "xyzpdq",
      "groups": []
    }