remove duplicate notify calls on wearable disconnect

Author: DennisMoschina

open_wearable/lib/view_models/sensor_recorder_provider.dart

@@ -72,7 +72,6 @@ class SensorRecorderProvider with ChangeNotifier {
 
     wearable.addDisconnectListener(() {
       removeWearable(wearable);
-      notifyListeners();
     });
 
     if (wearable.hasCapability<SensorManager>()) {

open_wearable/lib/view_models/wearables_provider.dart

@@ -252,7 +252,6 @@ class WearablesProvider with ChangeNotifier {
     // Disconnect listener (sync)
     wearable.addDisconnectListener(() {
       removeWearable(wearable);
-      notifyListeners();
     });
 
     // Notify ASAP so UI updates with the newly connected device