Question Unity Android Plugin Activity not Found

I'm currently trying to implement a notification system for an android game and need to open the app's native settings to help the user reenable the notification, when previosly turned off. I wrote a small andrid plugin and added it to the project.

Code (Java):

1. package com.example.plugin;
2.  
3. import android.app.Activity;
4. import android.net.Uri;
5. import android.content.*;
6. import android.provider.Settings;
7.  
8. public class NotificationPlugin {
9.     public void openSettings(Activity unityActivity) {
10.          Intent i = new Intent(Settings.ACTION_APPLICATION_SETTINGS,
11.             Uri.parse("package:" + unityActivity.getPackageName()));
12.  
13.         unityActivity.startActivity(i);
14.     }
15. }

I added these lines to the custom AndroidManifest.xml in unity.

Code (xml):

1. <intent-filter>
2.   <action android:name="android.settings.APPLICATION_SETTINGS" />
3.   <category android:name="android.intent.category.DEFAULT" />
4. </intent-filter>

And i'm accessing the method in a c# wrapper class with this method.

Code (CSharp):

1. public static void OpenNotificationSettings() {
2.     AndroidJavaClass unityPlayer = new AndroidJavaClass("com.unity3d.player.UnityPlayer");
3.     unityActivity = unityPlayer.GetStatic<AndroidJavaObject>("currentActivity");
4.      
5.     pluginClass = new AndroidJavaClass(pluginName);
6.     pluginClass.Call("openSettings", unityActivity);
7. }

The variable `pluginName` is a constant string, containing the fully quialified package name of the plugin class.

Using logcat i can see the follwing exception when trying to execute this:

android.content.ActivityNotFoundException: No Activity found to handle Intent

Since i have no real experiences with either android nor using plugins in unity, i don't know what to do with the exception and where the issue in all of these layers lies.
Can anyone tell me how to fix this issue?

PS: I know that i could probably have done this without a plugin, but there are other methods in the plugin, that i need and i wanted to have all native android related code packed into one plugin.