[dotnet test] Add androidtest project template and dotnet run instrumentation support

[jonathanpeppers]

Context: #10683

Add a new androidtest .NET project template that creates an Android test project using MSTest with Microsoft.Testing.Platform. The template includes a TestInstrumentation class that runs tests via am instrument and reports results (passed/failed/skipped) back through Android's instrumentation protocol.

Add --instrument option to Microsoft.Android.Run so dotnet run can launch test projects via am instrument -w instead of am start.

Fix an issue where NuGet packages like MSTest add assemblies as both properly-resolved publish assets (with DestinationSubPath metadata) and as None items (without DestinationSubPath) that flow into _SourceItemsToCopyToPublishDirectory. When NuGet conflict resolution arbitrarily picks the None-based copy, the assembly loses its DestinationSubPath and TargetPath metadata, causing it to either be missing from the APK or deployed to the wrong directory on device. The fix conditionally removes only items without DestinationSubPath, then re-adds any assemblies that were completely stripped with a cleared TargetPath so that downstream targets (ProcessAssemblies, FastDeploy) can set the correct per-architecture paths.

Changes:

• New androidtest template under src/Microsoft.Android.Templates/
• New GetAndroidInstrumentationName MSBuild task to resolve the instrumentation runner class from AndroidManifest.xml
• Updated Microsoft.Android.Sdk.Application.targets to pass --instrument when EnableMSTestRunner is true
• Added AdbHelper class to Microsoft.Android.Run for shared adb process management
• Added --instrument CLI option to Microsoft.Android.Run/Program.cs
• Fixed _ComputeFilesToPublishForRuntimeIdentifiers to preserve properly-resolved publish assets and recover missing assemblies
• Added DotNetNewAndroidTest device integration test

TODO:

• In a future PR, add support for dotnet test end-to-end.

[Copilot]

Pull request overview

This PR adds first-class support for Android device test projects driven by MSTest + Microsoft.Testing.Platform by introducing a new androidtest template and enabling dotnet run to launch via Android instrumentation (am instrument) instead of launching an activity.

Changes:

• Adds an androidtest project template that includes an Instrumentation entry point which runs tests and reports results via instrumentation bundles.
• Extends Microsoft.Android.Run with a new --instrument mode for am instrument -w execution.
• Updates MSBuild targets to locate instrumentation runners from the manifest and adjusts inner-build publish/assembly resolution behavior for certain NuGet package asset patterns.

Reviewed changes

Copilot reviewed 12 out of 12 changed files in this pull request and generated 6 comments.

Show a summary per file

File	Description
tests/MSBuildDeviceIntegration/Tests/InstallAndRunTests.cs	Adds a device integration test validating dotnet new androidtest + dotnet run instrumentation output.
src/Xamarin.Android.Build.Tasks/Tasks/GetAndroidInstrumentationName.cs	New MSBuild task to extract the instrumentation runner from the manifest.
src/Xamarin.Android.Build.Tasks/Microsoft.Android.Sdk/targets/Microsoft.Android.Sdk.AssemblyResolution.targets	Adds a target that mutates @(None)/@(Reference) metadata to influence publish asset selection.
src/Xamarin.Android.Build.Tasks/Microsoft.Android.Sdk/targets/Microsoft.Android.Sdk.Application.targets	Wires up the new task and passes --instrument to Microsoft.Android.Run when applicable.
src/Microsoft.Android.Templates/androidtest/*	New androidtest template files (csproj, manifest, tests, instrumentation runner, template config).
src/Microsoft.Android.Run/Program.cs	Adds --instrument option and async instrumentation execution path.
src/Microsoft.Android.Run/AdbHelper.cs	Introduces shared adb process start/run helpers.

[Copilot]

processExited is created but never used. This is dead code and can introduce warnings; please remove it or wire it up (e.g., via process.Exited) if you intended to signal when async output collection is complete.

Suggested change

var processExited = new ManualResetEventSlim (false);

[Copilot]

This task logs hard-coded, non-localized errors via Log.LogError(...) and introduces new error text without an XA/APT code. In this repo, MSBuild task errors are expected to use coded errors and localized strings from Properties.Resources (e.g., Log.LogCodedError("XA####", Properties.Resources.XA####, ...)). Please add appropriate resource entries + error code(s) and use coded logging instead of raw strings.

Suggested change

	Log.LogError ("The <instrumentation> element is missing the android:name attribute.");
	return false;
	}
	return !Log.HasLoggedErrors;
	}
	}
	Log.LogError ("No <instrumentation> element found in AndroidManifest.xml.");
	Log.LogCodedError ("XA1040", Properties.Resources.XA1040);
	return false;
	}
	return !Log.HasLoggedErrors;
	}
	}
	Log.LogCodedError ("XA1041", Properties.Resources.XA1041);

[Copilot]

XmlReader.Create(ManifestFile) will throw if the file is missing/invalid XML, which will surface as an unhandled task exception instead of a clean MSBuild error. Consider following the pattern used by GetAndroidActivityName (load via AndroidAppManifest.Load(...)) or explicitly validate ManifestFile exists and catch/convert XML exceptions into a coded MSBuild error.

[Copilot]

_NoneAssembliesToPromote will match any @(None) item ending in .dll with CopyToOutputDirectory set (including user-authored content/native DLLs with no %(Link)), then promotes it to @(Reference). This can cause ResolveReferences failures (e.g., BadImageFormat) or unintended reference graph changes for non-managed DLLs. Please tighten the criteria to only promote known NuGet package-provided managed assemblies (e.g., items coming from packages/targets, or with explicit metadata) and avoid mutating all @(Reference) items globally if possible.

[jonathanpeppers]

🤖 AI Review Summary

Verdict: ⚠️ Needs Changes

CI Status: All checks are still pending/in-progress.

Found 4 issues: 1 error, 3 warnings

• ❌ MSBuild tasks: Log.LogError without XA error code in GetAndroidInstrumentationName (GetAndroidInstrumentationName.cs:29,36)
• ⚠️ Nullable: Missing #nullable enable in new AdbHelper.cs (AdbHelper.cs:1)
• ⚠️ Thread safety: Non-atomic counter increments in TestInstrumentation template with parallel execution (TestInstrumentation.cs:93)
• ⚠️ Error handling: Empty catch blocks in RunInstrumentationAsync (Program.cs:235,247)

👍 What's good:

• Clean refactor of sync RunAdb → async AdbHelper.RunAsync with proper async/await throughout
• Well-documented _PatchNuGetReferenceMetadata target with clear comments explaining the NuGet assembly resolution fix
• Good use of XmlReader (streaming) and .IsNullOrEmpty() NRT extension in the new MSBuild task
• Comprehensive DotNetNewAndroidTest integration test covering pass/fail/skip scenarios
• Clean mutual exclusion between --activity and --instrument with clear user-facing error messages

---

Review generated by android-reviewer from review guidelines.

[jonathanpeppers]

🤖 ⚠️ Nullable — New files should have #nullable enable as the very first line, with no preceding blank lines.

Rule: #nullable enable on new files

[jonathanpeppers]

We should check if $(Nullable)=enable is set on this entire project or not. If it is, we don't need #nullable enable at the top and we should update instructions/code review rules to skip this comment next time.