Convert settings migration logic to kotlin

[dustdfg]

What is it?

• Codebase improvement (dev facing)

Description of the changes in your PR

• Convert settings migration logic to kotlin

APK testing

The APK can be found by going to the "Checks" tab below the title. On the left pane, click on "CI", scroll down to "artifacts" and click "app" to download the zip file which contains the debug APK of this PR. You can find more info and a video demonstration on this wiki page.

Due diligence

• I read the contribution guidelines.
• The proposed changes follow the AI policy.
• $${\color{red}NO AT ALL, BASICALLY CAN'T}$$ I tested the changes using an emulator or a physical device.

[theimpulson]

N O A T A L L , B A S I C A L L Y C A N ′ T I tested the changes using an emulator or a physical device.

Please don't open PRs blindly without adequate testing.

[dustdfg]

N O A T A L L , B A S I C A L L Y C A N ′ T I tested the changes using an emulator or a physical device.

Please don't open PRs blindly without adequate testing.

I'd like to test but I can't test it without having prepopulated dbs

[TobiGr]

Don't we have database migration tests? They seem to be fine.

[dustdfg]

Don't we have database migration tests? They seem to be fine.

DB migration while this PR is about settings migration...