Google Tag makes CSS aggregates uncacheable

Hey, guess what! This is a Drupal CMS stable blocker. See #3487542-13: Add Google Tag recipe → .

@dharizza will post an MR here soon; if it can be merged in and put into a tagged release, we can get that recipe out the door.

Turns out this ain't the problem, so this is not a stable blocker for Drupal CMS. We'll open a new issue for the actual problem.