Guard primitive array value-manager routing

[simonrozsival]

Summary

• require the JNI runtime type to match the selected primitive-array marshaler before invoking array JNI APIs
• route non-array IList<T> handles through JavaConvert only when JNI confirms the object implements java.util.List
• apply the equivalent exact JNI signature and List-assignability guards to the trimmable PrimitiveArrayInfo path
• honor JniObjectReferenceOptions before all new invalid-cast failures

CheckJNI evidence and safety boundary

The reproducer passed a java.util.ArrayList handle while requesting IList<bool>. The reflection value manager selected JavaBooleanArray.ArrayMarshaler from the managed target type alone, leading CheckJNI to abort the process with jarray argument has non-array type: java.util.ArrayList. This change establishes the safety boundary before any array JNI call: only the matching primitive array signature (for example, [Z) may enter that marshaler. A non-array reference may enter collection conversion only when JNI IsInstanceOf confirms java.util.List; other objects and mismatched arrays fail with InvalidCastException. Failure paths dispose and invalidate transferred references according to the requested ownership options.

Retained behavior

A genuine Java primitive array still marshals to IList<T>, and genuine Java List implementations still use JavaConvert. The guard compares the actual JNI runtime type rather than rejecting IList<T> generally.

Tests

Added on-device coverage in JavaConvertTest for:

• java.util.ArrayList<Boolean> handle -> IList<bool>
• Java boolean[] handle -> IList<bool>
• Java String handle -> IList<bool> safely throws, preserving Copy and consuming CopyAndDispose
• Java int[] handle -> IList<bool> safely throws and consumes CopyAndDispose

Validation:

• dotnet build external/Java.Interop/src/Java.Interop/Java.Interop.csproj ... passed with 0 warnings/errors after the review fixes.
• On-device tests were not run locally because this worktree has no prepared local SDK (make prepare is required).
• A direct Mono.Android.csproj build reaches the repository prerequisite failure because bin/BuildDebug/net10.0/xa-prep-tasks.dll is absent.