Current Behavior:

When I set up my google mail service using this plugin, if I cancel the consent screen it returns to admin panel but throws an error that is unhandled by the plugin.

Expected Behavior:

Ideally, it should take me back to the keyring service listing admin screen and show a notice error that it's been canceled by user. This is easy to identify as the URL has error=access_denied in it when user cancels.

http://localhost:8082/wp-admin/tools.php?page=keyring&action=verify&service=google-mail&error=access_denied&state=1010

Screenshot: