The phoneCallEvents and rawPhoneCallEvents streams don't work

[mr-mmmmore]

phoneCallEvents
I have tried to use the phoneCallEvents stream but I receive no events at all. I have tried it on the following devices:

• iPhone 6 (iOS 12.4.9)
• Samsung Galaxy S8 Edge (Android 7)

For example this prints nothing, whatever the call received or sent from/to the device:

lib.FlutterPhoneState.phoneCallEvents.listen((event) {
    print('EVENT RECEIVED');
});

rawPhoneCallEvents
This stream works on the iPhone, but not on the Android phone: an event with null id and type is received when the app starts, and then nothing else.

The app uses Flutter 1.22.6.