Trimmer switches to reduce size (#5)

Some from xamarin-android, and some from SmolSharp.

DotNet/libdotnet.csproj

@@ -4,14 +4,26 @@
     <TargetFramework>net8.0</TargetFramework>
     <ImplicitUsings>enable</ImplicitUsings>
     <Nullable>enable</Nullable>
-    <InvariantGlobalization>true</InvariantGlobalization>
     <PublishAot>true</PublishAot>
     <PublishAotUsingRuntimePack>true</PublishAotUsingRuntimePack>
     <RuntimeIdentifier Condition=" '$(RuntimeIdentifier)' == '' ">linux-bionic-arm64</RuntimeIdentifier>
     <!-- SkiaSharp nightly feed -->
     <RestoreAdditionalProjectSources>https://aka.ms/skiasharp-eap/index.json</RestoreAdditionalProjectSources>
   </PropertyGroup>
 
+  <!-- Trimmer switches -->
+  <PropertyGroup Condition=" '$(Configuration)' == 'Release' ">
+    <!-- From Android workload: https://github.com/xamarin/xamarin-android/blob/80ee320ed0bb245768ba436b76f9309aca18abc3/src/Xamarin.Android.Build.Tasks/Microsoft.Android.Sdk/targets/Microsoft.Android.Sdk.DefaultProperties.targets#L95-L110 -->
+    <InvariantGlobalization>true</InvariantGlobalization>
+    <UseSystemResourceKeys>true</UseSystemResourceKeys>
+    <NullabilityInfoContextSupport>false</NullabilityInfoContextSupport>
+    <_AggressiveAttributeTrimming>true</_AggressiveAttributeTrimming>
+    <!-- From SmolSharp: https://github.com/ascpixi/smolsharp/blob/54a4aeb6e8f6cdd64d049862dee611301082e71b/src/SmolSharp.props#L48-L57 -->
+    <IlcDisableReflection>true</IlcDisableReflection>
+    <StackTraceSupport>false</StackTraceSupport>
+    <OptimizationPreference>Size</OptimizationPreference>
+  </PropertyGroup>
+
   <ItemGroup>
     <!-- https://github.com/exelix11/SysDVR/blob/master/Client/Client.csproj -->
     <!-- Android needs a proper soname property or it will refuse to load the library -->

README.md

@@ -30,7 +30,7 @@ The C# side is a:
 
 ## App Size
 
-The release `.apk` file of the SkiaSharp sample is ~4.5 MB
+The release `.apk` file of the SkiaSharp sample is ~4.26 MB
 
 A breakdown of the files inside:
 
@@ -41,7 +41,7 @@ A breakdown of the files inside:
 1981-01-01 01:01:02 .....           56           52  META-INF\com\android\build\gradle\app-metadata.properties
 1981-01-01 01:01:02 .....         1524          753  classes.dex
 1981-01-01 01:01:02 .....      8525024      3733033  lib\arm64-v8a\libSkiaSharp.so
-1981-01-01 01:01:02 .....      1971400       846961  lib\arm64-v8a\libdotnet.so
+1981-01-01 01:01:02 .....      1070792       473191  lib\arm64-v8a\libdotnet.so
 1981-01-01 01:01:02 .....        19504         6869  lib\arm64-v8a\libnativeaot.so
 1981-01-01 01:01:02 .....         2376          867  AndroidManifest.xml
 1981-01-01 01:01:02 .....         7778         7778  res\-6.webp
@@ -60,19 +60,19 @@ A breakdown of the files inside:
 1981-01-01 01:01:02 .....         3918         3918  res\u5.webp
 1981-01-01 01:01:02 .....         1772         1772  res\yw.webp
 1981-01-01 01:01:02 .....         2036         2036  resources.arsc
-1981-01-01 01:01:02 .....         2085         1127  META-INF\CERT.SF
-1981-01-01 01:01:02 .....         1167         1017  META-INF\CERT.RSA
-1981-01-01 01:01:02 .....         2011         1050  META-INF\MANIFEST.MF
+1981-01-01 01:01:02 .....         2085         1122  META-INF\CERT.SF
+1981-01-01 01:01:02 .....         1167         1021  META-INF\CERT.RSA
+1981-01-01 01:01:02 .....         2011         1046  META-INF\MANIFEST.MF
 ------------------- ----- ------------ ------------  ------------------------
-1981-01-01 01:01:02           10569629      4629574  25 files
+1981-01-01 01:01:02            9669021      4255799  25 files
 ```
 
-`libdotnet.so` is ~1.9MB, and `libSkiaSharp.so` is ~8.5MB!
+`libdotnet.so` is ~1.07 MB, and `libSkiaSharp.so` is ~8.5MB!
 
 If we reduce this to a "Hello World" example:
 
-* `hello.apk` is ~561 KB!
-* `libdotnet.so` (uncompressed) is ~1.1 MB
+* `hello.apk` is ~430 KB!
+* `libdotnet.so` (uncompressed) is ~821 KB!
 
 ## "Hello World" Example