[flutter_local_notification_linux] fixed definition and registration of Linux implementation (#2371)

* fixed Linux pubspec to specify Linux platform implementation details

* added missing registerWith method

* updated changelog

Author: MaikuB

Diff for: flutter_local_notifications_linux/CHANGELOG.md

@@ -1,3 +1,7 @@
+## [4.0.1]
+
+* Fixed issue [#2368](https://github.com/MaikuB/flutter_local_notifications/issues/2368). This involved updating pubspec so it defines that it implements the Linux implementation of `flutter_local_notifications` and updating the code so it registers the Linux implementation
+
 ## [4.0.0+1]
 
 * Bumped maximum Dart SDK constraint

Diff for: flutter_local_notifications_linux/lib/src/flutter_local_notifications.dart

@@ -20,6 +20,12 @@ class LinuxFlutterLocalNotificationsPlugin
     LinuxNotificationManager manager,
   ) : _manager = manager;
 
+  /// Registers the Linux implementation.
+  static void registerWith() {
+    FlutterLocalNotificationsPlatform.instance =
+        LinuxFlutterLocalNotificationsPlugin();
+  }
+
   final LinuxNotificationManager _manager;
 
   /// Initializes the plugin.

Diff for: flutter_local_notifications_linux/pubspec.yaml

@@ -1,8 +1,16 @@
 name: flutter_local_notifications_linux
 description: Linux implementation of the flutter_local_notifications plugin
-version: 4.0.0+1
+version: 4.0.1
 homepage: https://github.com/MaikuB/flutter_local_notifications/tree/master/flutter_local_notifications
 
+flutter:
+  plugin:
+    implements: flutter_local_notifications
+    platforms:
+      linux:
+        dartPluginClass: LinuxFlutterLocalNotificationsPlugin
+
+
 dependencies:
   dbus: ^0.7.8
   ffi: ^2.0.1