turn Raylib-cs.Android into android library

Raylib-cs.Android.Sample/AndroidManifest.xml

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+<?xml version="1.0" encoding="utf-8"?>
+<manifest xmlns:android="http://schemas.android.com/apk/res/android">
+  <application android:allowBackup="true" android:icon="@mipmap/appicon"
+    android:label="@string/app_name" android:roundIcon="@mipmap/appicon_round"
+    android:supportsRtl="true">
+  </application>
+  <uses-permission android:name="android.permission.INTERNET" />
+</manifest>

Raylib-cs.Android.Sample/Assembly.cs

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+[assembly: UsesFeature(GLESVersion = 0x00020000, Required = true)]

Raylib-cs.Android.Sample/MainActivity.cs

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+using System.Runtime.InteropServices;
+using Android.Content;
+using Android.Content.PM;
+
+namespace Raylib_cs.Android;
+
+[
+    Activity(
+        Label = "@string/app_name",
+        MainLauncher = true,
+        ConfigurationChanges = ConfigChanges.Orientation
+            | ConfigChanges.KeyboardHidden
+            | ConfigChanges.ScreenSize,
+        ScreenOrientation = ScreenOrientation.Landscape,
+        ClearTaskOnLaunch = true
+    ),
+    IntentFilter(new[] { Intent.ActionMain }),
+    MetaData(NativeActivity.MetaDataLibName, Value = "raylib")
+]
+public class MainActivity : RaylibActivity
+{
+    protected override void OnReady()
+    {
+        Raylib.InitWindow(0, 0, "android_window");
+        while (!Raylib.WindowShouldClose())
+        {
+            Raylib.BeginDrawing();
+            Raylib.ClearBackground(Color.WHITE);
+            Raylib.DrawFPS(10, 10);
+            Raylib.DrawText("Hello Raylib-cs.Android", 20, 100, 100, Color.BLACK);
+            Raylib.EndDrawing();
+        }
+    }
+}

Raylib-cs.Android.Sample/README.md

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+```sh
+# clear nuget local cache if you install raylib-cs from nuget before
+dotnet nuget locals all --clear
+
+# install android sdk requirements
+# or just install it from visual studio
+sdkmanager "build-tools;34.0.0" "ndk;25.2.9519653" "platforms;android-34"
+
+# install android workload
+dotnet workload install android
+
+# download artifact.zip from https://github.com/anggape/Raylib-cs/actions/runs/5630394074 and extract it
+dotnet restore --source <path to extracted artifact.zip>
+
+# connect your android device or create new emulator
+adb devices # make sure your device there
+
+# run project
+dotnet run
+```

Raylib-cs.Android.Sample/Raylib-cs.Android.Sample.csproj

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+<Project Sdk="Microsoft.NET.Sdk">
+  <PropertyGroup>
+    <TargetFramework>net7.0-android</TargetFramework>
+    <SupportedOSPlatformVersion>21</SupportedOSPlatformVersion>
+    <RootNamespace>Raylib_cs.Android.Sample</RootNamespace>
+    <OutputType>Exe</OutputType>
+    <Nullable>enable</Nullable>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <ApplicationId>com.raylib.cs</ApplicationId>
+    <ApplicationVersion>1</ApplicationVersion>
+    <ApplicationDisplayVersion>1.0</ApplicationDisplayVersion>
+    <EmbedAssembliesIntoApk Condition="$(Configuration) == 'Debug'">true</EmbedAssembliesIntoApk>
+  </PropertyGroup>
+  <ItemGroup>
+    <PackageReference Include="Raylib-cs" Version="4.5.0.2" />
+    <ProjectReference Include="../Raylib-cs.Android/Raylib-cs.Android.csproj" />
+  </ItemGroup>
+</Project>

Raylib-cs.Android.Sample/Resources/AboutResources.txt

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+Images, layout descriptions, binary blobs and string dictionaries can be included 
+in your application as resource files.  Various Android APIs are designed to 
+operate on the resource IDs instead of dealing with images, strings or binary blobs 
+directly.
+
+For example, a sample Android app that contains a user interface layout (main.xml),
+an internationalization string table (strings.xml) and some icons (drawable-XXX/icon.png) 
+would keep its resources in the "Resources" directory of the application:
+
+Resources/
+    drawable/
+        icon.png
+
+    layout/
+        main.xml
+
+    values/
+        strings.xml
+
+In order to get the build system to recognize Android resources, set the build action to
+"AndroidResource".  The native Android APIs do not operate directly with filenames, but 
+instead operate on resource IDs.  When you compile an Android application that uses resources, 
+the build system will package the resources for distribution and generate a class called "Resource" 
+(this is an Android convention) that contains the tokens for each one of the resources 
+included. For example, for the above Resources layout, this is what the Resource class would expose:
+
+public class Resource {
+    public class Drawable {
+        public const int icon = 0x123;
+    }
+
+    public class Layout {
+        public const int main = 0x456;
+    }
+
+    public class Strings {
+        public const int first_string = 0xabc;
+        public const int second_string = 0xbcd;
+    }
+}
+
+You would then use Resource.Drawable.icon to reference the drawable/icon.png file, or 
+Resource.Layout.main to reference the layout/main.xml file, or Resource.Strings.first_string 
+to reference the first string in the dictionary file values/strings.xml.

Raylib-cs.Android.Sample/Resources/layout/activity_main.xml

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+<?xml version="1.0" encoding="utf-8"?>
+<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
+    xmlns:app="http://schemas.android.com/apk/res-auto"
+    xmlns:tools="http://schemas.android.com/tools"
+    android:layout_width="match_parent"
+    android:layout_height="match_parent">
+    <TextView 
+        android:layout_width="wrap_content"
+        android:layout_height="wrap_content"
+        android:layout_centerInParent="true"
+        android:text="@string/app_text"
+    />
+</RelativeLayout>

Raylib-cs.Android.Sample/Resources/mipmap-anydpi-v26/appicon.xml

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+<adaptive-icon xmlns:android="http://schemas.android.com/apk/res/android">
+  <background android:drawable="@mipmap/appicon_background" />
+  <foreground android:drawable="@mipmap/appicon_foreground" />
+</adaptive-icon>

Raylib-cs.Android.Sample/Resources/mipmap-anydpi-v26/appicon_round.xml

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+<adaptive-icon xmlns:android="http://schemas.android.com/apk/res/android">
+  <background android:drawable="@mipmap/appicon_background" />
+  <foreground android:drawable="@mipmap/appicon_foreground" />
+</adaptive-icon>