fix: failed to write libxamarin-app.so (#4400)

* fix: failed to write libxamarin-app.so

Another try at #4091

The theory is that it might be related to the restore operation rather than the build:
https://github.com/getsentry/sentry-dotnet/blob/25a2d578cd35766fcccf9e9fbab660d238640fdf/test/Sentry.Android.AssemblyReader.Tests/Sentry.Android.AssemblyReader.Tests.csproj#L19-L26

In CI we run the restore once, separate from the build... so this PR attempts to restore the `AndroidTestApp` in the same way (rather than as a dependency of the `BuildTestAPKs` target).

#skip-changelog

* Update Sentry.Android.AssemblyReader.Tests.csproj

* Add AndroidTestApp to solution (so no special restore operation is required)

* Revert "Add AndroidTestApp to solution (so no special restore operation is required)"

This reverts commit 7eca52f.

* Use Run Target Exactly Once trick...

* Update Sentry.Android.AssemblyReader.Tests.csproj

* Update test/Sentry.Android.AssemblyReader.Tests/Sentry.Android.AssemblyReader.Tests.csproj

Author: jamescrosswell

test/Sentry.Android.AssemblyReader.Tests/Sentry.Android.AssemblyReader.Tests.csproj

@@ -17,16 +17,21 @@
   </ItemGroup>
 
   <!-- Target to ensure AndroidTestApp is restored -->
-  <Target Name="EnsureAndroidTestAppRestored" Condition="'$(TargetPlatformIdentifier)' != 'android' and '$(AndroidTestAppRestored)' != 'true'">
-    <!-- Only restore once. Spawn as a separate process to escape any "no-restore" arguments to the build -->
+  <Target Name="EnsureAndroidTestAppRestored"
+          Condition="!Exists('$(MSBuildProjectDirectory)\..\AndroidTestApp\obj\project.assets.json')">
+    <Message Importance="high" Text="Restoring AndroidTestApp via MSBuild task..." />
     <Exec Command="dotnet restore ../AndroidTestApp/AndroidTestApp.csproj --nologo" />
-    <PropertyGroup>
-      <AndroidTestAppRestored>true</AndroidTestAppRestored>
-    </PropertyGroup>
   </Target>
 
+  <!-- Restore exactly once: https://learn.microsoft.com/en-gb/visualstudio/msbuild/run-target-exactly-once -->
+  <Target Name="BuildTestAPKsBeforeOuterBuild" DependsOnTargets="EnsureAndroidTestAppRestored"
+          Condition="'$(TargetPlatformIdentifier)' != 'android'"
+          BeforeTargets="DispatchToInnerBuilds" />
+
   <!--  Build the Android test app in various configurations during the build of this test project. -->
-  <Target Name="BuildTestAPKs" BeforeTargets="DispatchToInnerBuilds;BeforeBuild" DependsOnTargets="EnsureAndroidTestAppRestored" Condition="'$(TargetPlatformIdentifier)' != 'android'">
+  <Target Name="BuildTestAPKs" BeforeTargets="BeforeBuild" Condition="'$(TargetPlatformIdentifier)' != 'android'">
+    <!-- Restore exactly once: https://learn.microsoft.com/en-gb/visualstudio/msbuild/run-target-exactly-once -->
+    <MSBuild Projects="$(MSBuildProjectFullPath)" Targets="EnsureAndroidTestAppRestored" RemoveProperties="TargetFramework" />
     <MSBuild Projects="$(MSBuildProjectFile)" Targets="_InnerBuildTestAPKs" Properties="TargetFramework=net8.0-android" Condition="$(TargetFramework) == 'net8.0'" />
     <MSBuild Projects="$(MSBuildProjectFile)" Targets="_InnerBuildTestAPKs" Properties="TargetFramework=net9.0-android" Condition="$(TargetFramework) == 'net9.0'" />
   </Target>