Since the repo updates are happening in an IntentService, they are already
running in a separate thread. Ironically, the dialog was showing in spite
of that. This removes the dialog entirely and instead puts up a
Notification with the same messages. Ultimately, the "refresh" button
should go away, the repos should be updated whenever someone goes to
install an app, and all APK downloads should also show up in the same
Notification.
This removes UpdateReceiver entirely and replaces it with local broadcasts,
since that is a common pattern in FDroid and Android. It also reduces the
amount of code here.
refs #103https://gitlab.com/fdroid/fdroidclient/issues/103
4fd914ac7a