MacOS applications upload is not supported right now in appcenter-plugin.

When trying to upload  "*.app.zip"  file, it doesn't pass a validation that expects only Android or iOS binary (see discussion in:
https://github.com/jenkinsci/appcenter-plugin/pull/37#issuecomment-554527091)

It would be great to have that feature in, as that's the only major missing piece after migration from Hockey.

Thanks