Updated app icon & launcher image

android/app/src/main/res/values-night/styles.xml

@@ -5,6 +5,7 @@
         <!-- Show a splash screen on the activity. Automatically removed when
              the Flutter engine draws its first frame -->
         <item name="android:windowBackground">@drawable/launch_background</item>
+
     </style>
     <!-- Theme applied to the Android Window as soon as the process has started.
          This theme determines the color of the Android Window while your
@@ -13,6 +14,6 @@
 
          This Theme is only used starting with V2 of Flutter's Android embedding. -->
     <style name="NormalTheme" parent="@android:style/Theme.Black.NoTitleBar">
-        <item name="android:windowBackground">?android:colorBackground</item>
+        <item name="android:windowBackground">@drawable/launch_background</item>
     </style>
 </resources>