feat(settings): pick the MAC address source from a bottom sheet

[usamaiqb]

Replace the segmented buttons with a picker sheet like the language one. Each option shows whether it is ready, will prompt, or is unavailable; the sheet stays open while access is requested and shows a refusal inline instead of a Toast.

Checklist

• PR title follows Conventional Commits
• ./gradlew test and ./gradlew lint pass locally
• UI changes include screenshots / screen recordings (if applicable)

[usamaiqb]

@martinellimarco can you please take a look

[martinellimarco]

@usamaiqb I've tested this on two devices, one using Shizuku and the other rooted, both with the permission granted and denied. Everything works fine for me.