I received the request several times, upload this module to CPAN. In these day, in Perl world, cpanm and Carton are useful tools for installing modules. And these tools use CPAN. I think it's time to upload this module to CPAN.
I filed an issue on GitHub below.
Also, it includes important changes. My module has OAuth2::Client. But I think it's not good namespace for CPAN world. I should rename the module to Google::API::OAuth2::Client. I filed it at #9.
Both of them will be solved soon.
I will let you know after fixing them and uploading to CPAN here and mailing list.