Bump external/Java.Interop from cf80deb to 120d8a7

Bumps [external/Java.Interop](https://github.com/xamarin/java.interop) from `cf80deb` to `120d8a7`.
- [Release notes](https://github.com/xamarin/java.interop/releases)
- [Commits](dotnet/java-interop@cf80deb...120d8a7)

---
updated-dependencies:
- dependency-name: external/Java.Interop
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <support@github.com>