Added Talkback Accessibility Strings in Settings Menus

[Jinko48]

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• I have tested my contribution on these devices:

• Virtual device Pixel 8 API 37.1, Android 17

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Description

Fixes #14924

I added accessibility strings for the menus that were defaulting to null. I just set them to the same string from app/src/main/res/values/strings.xml that AppSettingsFragment.kt is using so it would work across locales and languages. I haven't tested this on a virtual device or personal device yet, but I can attempt that before merging if necessary. The build does run to completion.

[Jinko48]

Tested talkback on virtual device, and it seems to use "Go Back" for the English text to speech. As far as I can tell it seems to work for other languages as well ("Volver" at least in Spanish).