main, use the default user volume.

lib/main.dart

@@ -267,7 +267,7 @@ class _HomeScreenState extends State<HomeScreen> {
         vibrate: true,
         androidFullScreenIntent: true, // wakes screen like clock app
         volumeSettings: VolumeSettings.fade(
-          volume: 0.8,
+          //volume: 0.8,
           fadeDuration: Duration(seconds: 60),
         ),
         notificationSettings: NotificationSettings(