Note: This module is now deprecated but will be kept on GitHub to avoid breaking production environments. The CloudFlare integration has been reimplemented as gnarea/gmail/cloudflare on the Terraform Registry.
This is a set of Terraform modules to manage MX records for Gmail in the G Suite (fka Google Apps). It's meant to be temporary until Terraform supports the functionality out-of-the-box.
You can't override the provider because Terraform doesn't support dynamic provider aliases.