Information provided by 'device_changes' event are not as complete as previously used 'device_updated' event. This is a regression with the new version of 'Bluetooth-Manager'.
In 4a-hal bluetooth plugin, we need to maintain a list of connected bluetooth compatible (A2DP, ...) devices to be able to switch between different streaming devices.
In previous version of 'Bluetooth-Manager', we used 'device_updated' event that communicate all the information about the device with the event.
But with 'device_changes' event, when a device connect/disconnect, we only receive few information. To maintain our list, we need more information than what is currently provided ('address', 'paired', 'uuids', 'name', ...) about the device.