Bump to dotnet/java-interop/main@2a1e1800

[jonpryor]

Changes: https://github.com/dotnet/java-interop/compare/9d997232f0ce3ca6a5f788b1cdb0fb9b2f978c84...2a1e180086889a33c844e337a865093ab65193e7

• dotnet/java-interop@2a1e1800: [generator] Fix StackOverflow when copying DIM via private interfaces (dotnet/java-interop#1261)
• dotnet/java-interop@f863351e: [generator] Only use [JniTypeSignatureAttribute] for JavaInterop1 (dotnet/java-interop#1266)
• dotnet/java-interop@56cfab93: [generator] Fix exception caused by incorrect nested type name. (dotnet/java-interop#1267)
• dotnet/java-interop@b656f7f5: [generator] Add support for skipInterfaceMethods (dotnet/java-interop#1265)