No using WorkManager while scheduling reliable asynchronous tasks

# Issue details

My name is Alejandro Mazuera-Rozo, I am a PhD Student at Universidad de los Andes, and at Università della Svizzera italiana. I am part of a research on the usage of network libraries within Android apps. As result of our research we identified some code locations that might have network related problems.

### Duplicate?
Have you searched the issues of this repository if your issue is already known? yes

### Actual behaviour

There might be a potential issue while scheduling reliable asynchronous tasks. We address within the **Steps to reproduce the issue** section the code locations that are related to such issue.

### Expected behaviour

As you might know, `WorkManager` is an API that makes it easy to schedule such tasks which are expected to run even if the app exits or the device restarts. The WorkManager API is a suitable and recommended replacement for all previous Android background scheduling APIs, including `FirebaseJobDispatcher`, `GcmNetworkManager`, and, in this particular case, `Job Scheduler`.

In order to address this issue we recommend you to visit:

1. https://developer.android.com/topic/libraries/architecture/workmanager
2. https://android-developers.googleblog.com/2019/11/unifying-background-task-scheduling-on.html

# Steps to reproduce the issue

1. Assess potential issue location
https://github.com/wallabag/android-app/blob/2481616f80dbaf16350cff460d143b0dfbfe7c9e/app/src/main/java/fr/gaulupeau/apps/Poche/service/WallabagJobService.java#L23-L24