Bug 1462415 - Delete onboarding system add-on r=Standard8,k88hudson
Differential Revision: https://phabricator.services.mozilla.com/D7772 --HG-- extra : moz-landing-system : lando
Differential Revision: https://phabricator.services.mozilla.com/D7772 --HG-- extra : moz-landing-system : lando