Added WiFi Assistant settings.

+ Added ability to setup Wifi Assistant.
- Removed 'Avoid poor connections' from WiFi Advance Settings.
- Removed 'Optimize Wi-Fi' from WiFi Advance Settings.
+ Replaced checkboxes with switches in WifFI Advance Settings.
+ Added horizontal rule to seperate MAC/IP address text.

Bug: 15698824
Change-Id: Ia319ff5fb2566854666a07d0e77c8816a49fd3d6