Fix GridView.Adapter CA1416 false positive

[jonathanpeppers]

Summary

• match removed property accessors against supported Java base methods
• handle setters that specialize generic base setter type parameters without matching unrelated concrete generic types
• add focused positive and negative generator regression coverage
• add end-to-end analyzer regression coverage for GridView.Adapter
• preserve the existing regression cases for FrameLayout.Foreground, ListView.Adapter, and MediaStore.DateTaken

Context

This finishes the regression coverage and generator work started in:

• Bump to dotnet/java-interop/main@ef82a07a #10510
• [generator] Fix UnsupportedOSPlatform for property setters when base has getter-only java-interop#1374

The relevant history is:

• [generator] Don't mark a method as [UnsupportedOSPlatform] if it overrides a supported base method. java-interop#1313 introduced suppression of [UnsupportedOSPlatform] on supported overrides.
• [generator] FixupMethodOverrides() checks properties java-interop#1366 extended that handling to properties.
• Revert changes to [UnsupportedOSPlatform] java-interop#1367 reverted the platform-attribute changes from release/10.0.1xx to reduce risk for .NET 10: dotnet/java-interop@0ad0d40
• The changes remained on main, where the generic GridView.Adapter setter case was investigated in the unfinished Java.Interop PR above but left unresolved.

Java.Interop is now integrated into this repository, so this applies the focused generator fix directly in-tree.

Testing

• all 466 Java.Interop generator tests pass
• positive mutation checks fail when the accessor fix is disabled
• the concrete-generic guard fails with the previous broad IsGeneric match
• the 10-case Android BuildHasNoWarnings matrix passes, with the three unsupported Debug NativeAOT cases skipped

Fixes: #12107

[Copilot]

Pull request overview

This PR updates the in-tree Java.Interop generator override/fixup logic to prevent a CA1416 false-positive on Android.Widget.GridView.Adapter.set by recognizing when a “removed” property accessor is actually satisfied by a supported base-class Java method (including generic-specialization cases). It also adds regression coverage in both generator unit tests and an end-to-end BuildHasNoWarnings build test.

Changes:

• Update GenBase.FixupMethodOverrides() to clear ApiRemovedSince on property accessors when a matching supported base Java method exists (including a special-case for setters overriding a generic base setter parameter).
• Add a Java.Interop generator regression test for GridView.Adapter.
• Add an Android build regression snippet to ensure no warnings for FrameLayout.Foreground, GridView.Adapter, ListView.Adapter, and MediaStore.*.DateTaken.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 2 comments.

File	Description
src/Xamarin.Android.Build.Tasks/Tests/Xamarin.Android.Build.Tests/BuildTest2.cs	Adds end-to-end “no warnings” regression usage for the affected APIs, including GridView.Adapter setter.
external/Java.Interop/tools/generator/Java.Interop.Tools.Generator.ObjectModel/GenBase.cs	Adjusts accessor-vs-base-method matching for ApiRemovedSince fixup to avoid false “unsupported” annotations.
external/Java.Interop/tests/generator-Tests/Unit-Tests/CodeGeneratorTests.cs	Adds a generator regression test intended to cover the GridView.Adapter scenario.