[build] Disable CoreCLR ReadyToRun without trimming

[jonathanpeppers]

Summary

• disable CoreCLR ReadyToRun and composite ReadyToRun when trimming is disabled
• emit XA0119 explaining that PublishTrimmed=true is required to use ReadyToRun
• keep non-trimmed assemblies as IL so _LinkAssembliesNoShrink can safely apply FixAbstractMethodsStep
• add coverage for the binding-assembly rewrite that previously failed with XALNS7015

Testing

• Xamarin.Android.Build.Tests builds successfully
• FixAbstractMethodsOnReadyToRunAssembly passes and asserts the XA0119 warning

Fixes: #11025

[Copilot]

Pull request overview

Adds/adjusts test coverage in Xamarin.Android.Build.Tests to reproduce the CoreCLR Release (non-trimmed) failure path where FixAbstractMethodsStep attempts to rewrite a ReadyToRun (R2R) assembly and Mono.Cecil cannot write mixed-mode assemblies, without changing product behavior.

Changes:

• Removes the previously-ignored CoreCLR/non-trimmed variant of SimilarAndroidXAssemblyNames.
• Adds a new focused test intended to exercise the CoreCLR Release + PublishTrimmed=false scenario that can trigger XALNS7015.

[jonathanpeppers]

/review

[github-actions]

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[github-actions]

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Generated by Android PR Reviewer for #12445 · gpt56 · 533.1 AIC · ⌖ 9.95 AIC · ⊞ 25.7K
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Comments that could not be inline-anchored

src/Xamarin.Android.Build.Tasks/Microsoft.Android.Sdk/targets/Microsoft.Android.Sdk.CoreCLR.targets:10

🤖 ❌ MSBuild targets — MSBuild global properties are immutable unless explicitly listed in TreatAsLocalProperty, so this assignment cannot disable PublishReadyToRun when it came from -p:PublishReadyToRun=true; the assignment on the next line likewise cannot disable a globally supplied PublishReadyToRunComposite. With -p:PublishTrimmed=false -p:PublishReadyToRun=true, _AndroidReadyToRunWithoutTrimming becomes true, but PublishReadyToRun remains true, so crossgen2 still runs…

Documentation/docs-mobile/messages/xa0119.md:48

🤖 ⚠️ Documentation — The main PublishReadyToRun reference in Documentation/docs-mobile/building-apps/build-properties.md still says CoreCLR Release builds default this property to true and that composite R2R follows it, without mentioning the new PublishTrimmed=true prerequisite. Please update that public property documentation as part of this behavior change so users do not receive conflicting guidance.

Rule: Public behavior documentation

src/Xamarin.Android.Build.Tasks/Microsoft.Android.Sdk/targets/Microsoft.Android.Sdk.CoreCLR.targets:21

🤖 ❌ MSBuild targets — This assignment cannot disable ReadyToRun when PublishReadyToRun was supplied as a global property (for example, dotnet publish -p:PublishReadyToRun=true -p:PublishTrimmed=false), because MSBuild global properties are immutable during project evaluation. In that common invocation the warning claims R2R was disabled, but crossgen2 still runs and the original mixed-mode rewrite failure remains. Please handle the global-property case (or fail it explicitly) and add a…