Mark HttpClient.Send tests uniformly with UnsupportedOSPlatform for Android, iOS

[eriawan]

Fixes #104716 by marking HttpClient.Send with UnsupportedOSPlatform with values of android, ios over eixisting.

Please review.

cc @wfurt , @ManickaP

[Copilot]

Pull Request Overview

This PR addresses issue #104716 by adding platform-specific annotations to mark HttpClient.Send methods as unsupported on Android and iOS platforms, in addition to the existing browser platform restriction.

Key changes:

• Added UnsupportedOSPlatform attributes for "android" and "ios" to synchronous Send methods
• Uncommented previously commented-out platform attributes in HttpClientHandler
• Updated both implementation and reference assembly files for consistency

Reviewed Changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 1 comment.

File	Description
HttpMessageInvoker.cs	Added android and ios platform restrictions to the base Send method
HttpClientHandler.AnyMobile.cs	Uncommented android and ios platform attributes for the Send method override
HttpClient.cs	Added android and ios platform restrictions to all four Send method overloads
System.Net.Http.cs	Updated reference assembly to reflect the new platform restrictions

Comments suppressed due to low confidence (1)

src/libraries/System.Net.Http/ref/System.Net.Http.cs:1

• Corrected malformed attribute name from 'UnsupportedOSPlatformAttributeUnsupportedOSPlatform' to 'UnsupportedOSPlatform'.

// Licensed to the .NET Foundation under one or more agreements.

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[eriawan]

Rebase again to main branch as of now.

[ManickaP]

LGTM, thanks!

[ManickaP]

Seems like the errors are relevant: API compatibility errors between 'ref/net10.0/System.Net.Http.dll' (left) and 'runtimes/win/lib/net10.0/System.Net.Http.dll' etc.

[eriawan]

Seems like the errors are relevant: API compatibility errors between 'ref/net10.0/System.Net.Http.dll' (left) and 'runtimes/win/lib/net10.0/System.Net.Http.dll' etc.

@ManickaP
I think those errors are not caused by my PR, they are closely related to this issue on dotnet/arcade: dotnet/arcade#7585

especially this comment: dotnet/arcade#7585 (comment)
Now that ApiCompat has been moved to dotnet/sdk. the problem is still there: dotnet/sdk#35542

[ManickaP]

No, you have to add the same set of attributes to src/libraries/System.Net.Http/src/System/Net/Http/HttpClientHandler.cs as well.
This reproduces locally, so you can test it out yourself.

[eriawan]

No, you have to add the same set of attributes to src/libraries/System.Net.Http/src/System/Net/Http/HttpClientHandler.cs as well. This reproduces locally, so you can test it out yourself.

@ManickaP thanks! you're right. Hopefully the CI should be green now.

[eriawan]

@ManickaP

I think those failed CI is not related to this PR, it says something about exception of SSL in Azure DevOps task.
Please review thia again, thanks!

[ManickaP]

/ba-g #121518

[eriawan]

Thanks @ManickaP ! 👍