Add Constructor in BluetoothDevice class

[ggola]

Needed a constructor to instantiate BluetoothDevice with persisted properties (id, name, type)

[boskokg]

You can create it from proto. eg:

protos.BluetoothDevice dev = protos.BluetoothDevice()
..remoteId = address;
_bleDevice = BluetoothDevice.fromProto(dev);