Fix crash with NSUrl implicit conversion and null

[chamons]

• Fixes: Implicit conversion from NSUrl? to Uri? crashes on null value #14786

Before fix test crashed with same:

System.NullReferenceException: Object reference not set to an instance of an object.
   at Foundation.NSUrl.op_Implicit(NSUrl url)

[rolfbjarne]

This would be a great opportunity to enable nullability in this file 😁

[mandel-macaque]

@rolfbjarne that's a trap! :P

[chamons]

I'll take a stab.

[chamons]

I added nullability as requested. @tj-devel709 please review my changes here.

[vs-mobiletools-engineering-service2]

📚 [PR Build] Artifacts 📚

Packages generated

View packages

• delete-xma-build-host.pkg
• Microsoft.iOS.Bundle.15.4.400-ci.pr.gh14860.13.pkg
• Microsoft.iOS.Ref.15.4.400-ci.pr.gh14860.13.nupkg
• Microsoft.iOS.Runtime.ios-arm.15.4.400-ci.pr.gh14860.13.nupkg
• Microsoft.iOS.Runtime.ios-arm64.15.4.400-ci.pr.gh14860.13.nupkg
• Microsoft.iOS.Runtime.iossimulator-arm64.15.4.400-ci.pr.gh14860.13.nupkg
• Microsoft.iOS.Runtime.iossimulator-x64.15.4.400-ci.pr.gh14860.13.nupkg
• Microsoft.iOS.Runtime.iossimulator-x86.15.4.400-ci.pr.gh14860.13.nupkg
• Microsoft.iOS.Sdk.15.4.400-ci.pr.gh14860.13.nupkg
• Microsoft.iOS.Templates.15.4.400-ci.pr.gh14860.13.nupkg
• Microsoft.iOS.Windows.Sdk.15.4.400-ci.pr.gh14860.13.nupkg
• Microsoft.MacCatalyst.Bundle.15.4.400-ci.pr.gh14860.13.pkg
• Microsoft.MacCatalyst.Ref.15.4.400-ci.pr.gh14860.13.nupkg
• Microsoft.MacCatalyst.Runtime.maccatalyst-arm64.15.4.400-ci.pr.gh14860.13.nupkg
• Microsoft.MacCatalyst.Runtime.maccatalyst-x64.15.4.400-ci.pr.gh14860.13.nupkg
• Microsoft.MacCatalyst.Sdk.15.4.400-ci.pr.gh14860.13.nupkg
• Microsoft.MacCatalyst.Templates.15.4.400-ci.pr.gh14860.13.nupkg
• Microsoft.macOS.Bundle.12.3.400-ci.pr.gh14860.13.pkg
• Microsoft.macOS.Ref.12.3.400-ci.pr.gh14860.13.nupkg
• Microsoft.macOS.Runtime.osx-arm64.12.3.400-ci.pr.gh14860.13.nupkg
• Microsoft.macOS.Runtime.osx-x64.12.3.400-ci.pr.gh14860.13.nupkg
• Microsoft.macOS.Sdk.12.3.400-ci.pr.gh14860.13.nupkg
• Microsoft.macOS.Templates.12.3.400-ci.pr.gh14860.13.nupkg
• Microsoft.NET.Sdk.iOS.Manifest-6.0.300.15.4.400-ci.pr.gh14860.13.nupkg
• Microsoft.NET.Sdk.MacCatalyst.Manifest-6.0.300.15.4.400-ci.pr.gh14860.13.nupkg
• Microsoft.NET.Sdk.macOS.Manifest-6.0.300.12.3.400-ci.pr.gh14860.13.nupkg
• Microsoft.NET.Sdk.tvOS.Manifest-6.0.300.15.4.400-ci.pr.gh14860.13.nupkg
• Microsoft.NET.Workload.iOS.15.4.400-ci.pr.gh14860.13.msi
• Microsoft.tvOS.Bundle.15.4.400-ci.pr.gh14860.13.pkg
• Microsoft.tvOS.Ref.15.4.400-ci.pr.gh14860.13.nupkg
• Microsoft.tvOS.Runtime.tvos-arm64.15.4.400-ci.pr.gh14860.13.nupkg
• Microsoft.tvOS.Runtime.tvossimulator-arm64.15.4.400-ci.pr.gh14860.13.nupkg
• Microsoft.tvOS.Runtime.tvossimulator-x64.15.4.400-ci.pr.gh14860.13.nupkg
• Microsoft.tvOS.Sdk.15.4.400-ci.pr.gh14860.13.nupkg
• Microsoft.tvOS.Templates.15.4.400-ci.pr.gh14860.13.nupkg
• xamarin.ios-15.11.0.131.pkg
• xamarin.mac-8.11.0.131.pkg

Pipeline on Agent XAMBOT-1098.Monterey'
Hash: b7509d741e473cec1621ff8d2803125953dbd5fe

[vs-mobiletools-engineering-service2]

💻 [PR Build] Tests on macOS Mac Catalina (10.15) passed 💻

✅ All tests on macOS Mac Catalina (10.15) passed.

Pipeline on Agent
Hash: b7509d741e473cec1621ff8d2803125953dbd5fe

[vs-mobiletools-engineering-service2]

❌ [PR Build] Tests on macOS M1 - Mac Big Sur (11.5) failed ❌

Failed tests are:

• xammac_tests
• monotouch-test

Pipeline on Agent
Hash: b7509d741e473cec1621ff8d2803125953dbd5fe

[vs-mobiletools-engineering-service2]

🔥 [PR Build] Build failed 🔥

Build failed for the job 'Generate API diff'

Pipeline on Agent
Hash:

[vs-mobiletools-engineering-service2]

✅ [CI Build] Tests passed on VSTS: simulator tests iOS. ✅

Tests passed on VSTS: simulator tests iOS.

• Azure DevOps
• Html Report (VSDrops) Download

🎉 All 148 tests passed 🎉

Pipeline on Agent XAMBOT-1105.Monterey'
Merge b7509d7 into 01c3127