new: add theme support with GwenedegTheme to take dark mode into account

androidApp/src/main/AndroidManifest.xml

@@ -8,7 +8,7 @@
         android:label="@string/app_name"
         android:roundIcon="@mipmap/ic_launcher_round"
         android:supportsRtl="true"
-        android:theme="@android:style/Theme.Material.Light.NoActionBar">
+        android:theme="@android:style/Theme.Material.NoActionBar">
         <activity
             android:exported="true"
             android:name=".MainActivity">