TODO(burdon): Preferences (in database).
Optional
from field: dxos.keys.PublicKey device_key = 1;
from field: dxos.client.services.DeviceKind kind = 2;
from field: dxos.client.services.Device.PresenceState presence = 4;
from field: optional dxos.halo.credentials.DeviceProfileDocument profile = 3;
from message dxos.client.services.Device
TODO(burdon): Preferences (in database).