[SettingsLib] Support master switch of inline toggle of Settings Injection v2

Allow developers to inject MasterSwitchPreference, a switch
preference with two tap targets, to Settings page.

Developers should declare keyhint and switch_uri for the activity
in AndroidManifest,and then implement a SwitchesProvider.

Bug: 132808482
Test: robotest
Change-Id: Id58ecd15475c428b3ae963831299b8bdf5e63e79