Fix icons and splash screens, build in gh actions workflow, remove resources from git

android/app/src/main/res/drawable-v21/launch_background.xml

@@ -1,9 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
-    <item>
-        <bitmap android:gravity="fill" android:src="@drawable/background"/>
-    </item>
-    <item>
-        <bitmap android:gravity="center" android:src="@drawable/splash"/>
-    </item>
-</layer-list>

android/app/src/main/res/drawable/launch_background.xml

@@ -1,9 +0,0 @@
-<?xml version="1.0" encoding="utf-8"?>
-<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
-    <item>
-        <bitmap android:gravity="fill" android:src="@drawable/background"/>
-    </item>
-    <item>
-        <bitmap android:gravity="center" android:src="@drawable/splash"/>
-    </item>
-</layer-list>

android/app/src/main/res/values-night-v31/styles.xml

@@ -2,6 +2,9 @@
 <resources>
     <!-- Theme applied to the Android Window while the process is starting when the OS's Dark Mode setting is on -->
     <style name="LaunchTheme" parent="@android:style/Theme.Black.NoTitleBar">
+        <!-- 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>
         <item name="android:forceDarkAllowed">false</item>
         <item name="android:windowFullscreen">false</item>
         <item name="android:windowDrawsSystemBarBackgrounds">false</item>

android/app/src/main/res/values-v31/styles.xml

@@ -2,6 +2,9 @@
 <resources>
     <!-- Theme applied to the Android Window while the process is starting when the OS's Dark Mode setting is off -->
     <style name="LaunchTheme" parent="@android:style/Theme.Light.NoTitleBar">
+        <!-- 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>
         <item name="android:forceDarkAllowed">false</item>
         <item name="android:windowFullscreen">false</item>
         <item name="android:windowDrawsSystemBarBackgrounds">false</item>

android/app/src/main/res/values/colors.xml

@@ -1,4 +1,4 @@
 <?xml version="1.0" encoding="utf-8"?>
 <resources>
-    <color name="launch_background">#202020</color>
+    <color name="launch_background">#152131</color>
 </resources>