use MaterialYou as activity design in ApplyTheme

Author: cracky22

src/keepass2android-app/Resources/values/strings.xml

@@ -1249,7 +1249,7 @@
   <string-array name="design_options">
     <item>Light</item>
     <item>Dark</item>
-    <item>Material You</item>
+    <item>MaterialYou</item>
     <item>System settings</item>
   </string-array>
   <string-array name="design_values">

src/keepass2android-app/Utils/ActivityDesign.cs

@@ -66,6 +66,11 @@ public void ApplyTheme()
       AppCompatDelegate.DefaultNightMode = _currentThemeId.Value;
       _secureWindow = SecureWindowPref();
 
+      if (IsMaterialYouEnabled && Build.VERSION.SdkInt >= BuildVersionCodes.S)
+      {
+          _activity.SetTheme(Resource.Style.Kp2aTheme_MaterialYou);
+      }
+
       _currentIconSet = PreferenceManager.GetDefaultSharedPreferences(_activity)
           .GetString("IconSetKey", _activity.PackageName);
     }