[Tests] Enable SubscribeToAppDomainUnhandledException on CoreCLR

[jonathanpeppers]

Description

MSBuildDeviceIntegration.InstallAndRunTests.SubscribeToAppDomainUnhandledException was previously skipped via Assert.Ignore for both CoreCLR and NativeAOT, with the reason "AppDomain.CurrentDomain.UnhandledException doesn''t work in CoreCLR or NativeAOT".

However, the rest of the test body was already wired up for CoreCLR:

string? expectedSender = runtime switch
{
    AndroidRuntime.MonoVM => "System.Object", // MonoVM passes the current domain as the sender
    AndroidRuntime.CoreCLR => null, // CoreCLR explicitly passes a `null` sender
    _ => throw new NotImplementedException($"Test does not support runtime {runtime}"),
};

…and IgnoreUnsupportedConfiguration(CoreCLR, release: true) already returns false (i.e. CoreCLR + Release is supported).

Change

Tighten the Assert.Ignore block so it only skips on NativeAOT, letting the test exercise AppDomain.CurrentDomain.UnhandledException on CoreCLR. With sender == null, the formatted logcat line becomes # Unhandled Exception: sender=; e.IsTerminating=True; e.ExceptionObject=System.Exception: CRASH, which the existing expectedSender switch already produces.

Test status on main (build 14389667)

Runtime	Before	After
MonoVM	✅ Passed	✅ Passed
CoreCLR	⏭️ NotExecuted	▶️ Now runs
NativeAOT	⏭️ NotExecuted	⏭️ NotExecuted (still skipped)

[Copilot]

Pull request overview

This PR updates the MSBuild device integration test suite to exercise AppDomain.CurrentDomain.UnhandledException on CoreCLR by narrowing an Assert.Ignore guard that previously skipped the test for both CoreCLR and NativeAOT.

Changes:

• Restrict SubscribeToAppDomainUnhandledException to skip only on AndroidRuntime.NativeAOT.
• Update the ignore message to reflect the new skip condition.