Fix provider crash when userinfo email is nil (#6839)
Fix provider crash when userinfo email is nil (#6839)

Fixes https://github.com/hashicorp/terraform-provider-google/issues/13051
GoogleCloudPlatform/magic-modules,GoogleCloudPlatform/magic-modules,GoogleCloudPlatform/magic-modules,GoogleCloudPlatform/magic-modules,GoogleCloudPlatform/magic-modules