[Hotfix] Disable PruneMedia Job from running in Background

[himeshr]

Describe the bug
This card is a hotfix for #1550
Disable PruneMedia Job from running in Background. We'll bring it back in a more efficient and user-friendly way as part of #1550

To Reproduce
Steps to reproduce the behavior:
Using any version of Avni APK,

• Login as noordeen@goonj org user (has extremely large number of observations)
• Perform sync
• Navigate to Activities list page and randomly download media-items (60, 70 items)
• Restart the app
• Observe that app splash screen stays on for longer and longer duration of time as we download more media-items

Developer Checklist
Developer fixing the bug should fill this checklist.

• Does the fix require extensive regression testing? No
• Are you mentioning the required scenarios that could be affected? App startup

[himeshr]

We have not been able to reproduce the actual issue reported here.. paired with Joy to figure out possible locations for the error, couldn't find any that could be hit in natural course of app load. Cards #1550 and #1551 are not gonna help resolve the issue reported in ticket https://avni.freshdesk.com/a/tickets/4975.

[himeshr]

On more debug while pairing with @petmongrels, by downloading close to 60 images on the app, found that the stalling on SplashScreen is caused by the PruneMedia Job itself..
Attached related screen-recording here https://drive.google.com/file/d/10C6SmyZ7XoQuSeOv3EHRn3R9lNZzcGj8/view?usp=sharing

[himeshr]

QA Prerelease APK: https://app.circleci.com/pipelines/github/avniproject/avni-client/2732/workflows/30d15f2b-1bb3-41a9-a12f-57413f8f601d/jobs/17683/artifacts