Update homepage summaries

- Network & internet
- Connected devices
- Display
- Wallpaper & style
- Accessibility
- Tips & support
- Also clear the redundant codes and tests.

Fixes: 183642373
Fixes: 189981034
Fixes: 190011428
Fixes: 190015037
Test: robotests & visual
Change-Id: Ide19fa5aff67e093d86b259c5e7a307b9ad37550