PushService.init is an async function waiting on a queue, thus it should be awaited to make sure the mock service registers before `PushService.unregister`. Differential Revision: https://phabricator.services.mozilla.com/D247795
PushService.init is an async function waiting on a queue, thus it should be awaited to make sure the mock service registers before `PushService.unregister`. Differential Revision: https://phabricator.services.mozilla.com/D247795