[Safety Labels] Polish UX for data sharing settings preference

- Use custom view for "settings button preference"
- Use @style extensively so everything in this view is overlayable
- Adjust margins/padding to match UX spec

Test: atest CtsPermission3TestCases:AppDataSharingUpdatesTest
Bug: 261666772
Change-Id: I0b87a93bdb3fcbc67c03f017be48af50ba18c6ef