ProvisioningKey: Some beacons may require a user to provide an authorization key before changing any of its configuration (e.g. broadcast frames, transmit power). This field provides a place to store and control access to that key. This field is populated in responses to `GET /v1beta1/beacons/3!beaconId` from users with write access to the given beacon. That is to say: If the user is authorized to write the beacon's confidential data in the service, the service considers them authorized to configure the beacon. Note that this key grants nothing on the service, only on the beacon itself.