Apply FooterPreference to the sub-pages of Special app access

Affected pages:
- Display over other apps
- Modify system settings
- Picture-in-picture
- Install unknown apps
- Usage access
- Wi-Fi control

Bug: 179234542
Test: robotests & visual
Change-Id: Icac09d0cf2b92cb5b74a8c5629e211108a78cdb0