Fix unreadable clock

Fix unreadable clock

- Always use white text with shadows on media
- Use lock screen colors for shade theme
- Remove legacy wallpaper visibility listener
- Remove shadow from black title

Test: set white wallpaper
Test: set dark wallpaper
Test: set dark wallpaper on home, light on ls
Test: set dark wallpaper on ls, light on home
Test: atest SysuiColorExtractorTests
Fixes: 134119878
Change-Id: I64ee2dee14322b2c02891c3ffe5fc0b25d1f100b