specify [site_name] value

see #1649128-2: add custom account name text-tag to differentiate GA accounts across staging sites, but there's no UI for it.

You can use drush vset ga_login_textid 'MyTeXtId' or change your settings.php file

$conf['ga_login_textid'] = 'MyTeXtId';

A patch to add a separate variable for the site name which defaults to the current site_name (for backwards-compatibility).

This is useful if you've got a long site name (that can't be changed, as it is used elsewhere) which makes GA Login usernames unwieldy. For example, your site name is University of Ontario Institute of Technology, which can be nicely represented as devin@uoit instead of devin@University of Ontario Institute of Technology.

Using something other than the site name can also be helpful if you're using the Variable module which allows the site name to be translated. It prevents users who are using different languages from having different logins.

@Devin Carlson #2 looks good, but it would be better if we had an admin form to handle those two variables, can you build one?

Admin UI added as well