We have to make some changes, and it's gotten to the point where
maintaining it as a separate library is more hassle than it's worth,
especially with Google releasing WorkManager as the preferred job
scheduling library.
This could be a sync message, delivery receipt, or some other
message that isn't user-visible. The push notification content
would need to indicate whether that's the case in order to be
able to accurately display a notification
// FREEBIE
