I think you are mixing something here. Google dropped OpenID years ago.
gerrit-oauth-provider that I maintain offers two major operation modes
(you can found detailed explanation on this Wiki site of this plugin: [1]):
* OAuth mode only
* Hybrid OpenID+OAuth authentication
Hybrid mode is important for LibreOffice developers, because some of them
still heavily use OpenID providers but some use OAuth providers on the same
gerrit installation site.
If all you want is to use Google's OAuth you should use OAuth mode and not
OpenID mode of this plugin. See also further documentation how to set up
OAuth providers for this plugin: [2].