K-9: Add support for background execution limits on Android 8+

[cketti]

See https://developer.android.com/about/versions/oreo/background

For minimal support we could make MailService and PushService foreground services. We also need to make sure at least one of them is started whenever we perform a background operation.

For a nicer solution we could look into making periodic syncs use JobIntentService. For Push we still need to use a foreground service. We probably want to create a separate notification channel. That way users will be able hide the ongoing notification required for a foreground service.

[dasgnu]

Are you planning to implement any of these solutions? If yes when will an updated version be ready? Thanks to the entire team that keeps developing K9.

[thomascas]

there is some news about this milestone? from 1 november is impossible to submit to store new versions without this target.

[Valodim]

Thoughts on using WorkManager for this?

[wiktor-k]

Is this ticket closed with #3763?

[cketti]

Is this ticket closed with #3763?

No. We still need to fix or disable Push.

[cmeng-git]

As proposed by android, the problem can be fixed by extending the services to use JobIntentService instead of CoreService (Service).

[Krammig]

With respect, I would hardly call this an Enhancement. Irrespective of the Play store criteria, even standalone apps cannot be targeted above API 25 and we are a long way past that.