Add workRequest to trigger ObserverService instead of ScheduledJob

Description

Add Work request to trigger ObserverService with Jetpack Work API rather than JobScheduler

Issue(s)

backlog#7

Test environment

Use latest pipeline to get the APK

Sign APK

Manually push on rooted device as eDrive is a persistent app right now

Test procedures

Full file scan is set to be trigger every 31 minutes with a flew time of 5 minutes. So every 31 minutes you must see message in logcat telling the FullScanWorker is doing it's work.

• This won't happen if there is no network of if battery is under 20%
• If you disabled both settings option in account (media sync & settings sync) you must see a warning logcat telling it doesn't have started ObserverService
• It must start ObserverService each time all conditions are met

Check list

• Self review
• Test procedure explained
• Tested on fresh install
• Tested applied as an update
• License
• Internal documentation