Add exclude from recents

Co-authored-by: Jannis Mattheis <contact@jmattheis.de>

app/src/main/kotlin/com/github/gotify/Utils.kt

@@ -1,6 +1,8 @@
 package com.github.gotify
 
 import android.app.Activity
+import android.app.ActivityManager
+import android.content.Context
 import android.content.res.Resources
 import android.graphics.Bitmap
 import android.graphics.drawable.BitmapDrawable
@@ -115,4 +117,9 @@ internal object Utils {
     fun interface DrawableReceiver {
         fun loaded(drawable: Drawable?)
     }
+
+    fun setExcludeFromRecent(context: Context, excludeFromRecent: Boolean) {
+        context.getSystemService(ActivityManager::class.java).appTasks?.getOrNull(0)
+            ?.setExcludeFromRecents(excludeFromRecent)
+    }
 }