Background
See https://phabricator.wikimedia.org/T334759#8794589
To improve app launch times, we could perform a one-time database housekeeper cleanup task call upon app launch.
Task
I suggest we show the migration "loading" animation in case it takes a while. We should take care that it can continue cleaning up where it left off in case the user backgrounds or terminates during this.
We should also maybe perform this cleanup task when the user taps "Clear cache" in app Settings
LOE
Estimated time: 1 week
Design Review Instructions
Possible Risks
Test Plan
Provide a way for QA to populate local database with a huge amount of explore feed data and articles. Use exported user libraries for data population ideas. Then have QA update with build and confirm they see updating animation with progress bar.