Add AppNotificationPreference to App Info Settings

This is only for the App Info Settings page, which is planed to be
migrated to SPA in Android U.

Currently protected by flag settings_enable_spa, default false.

This will not impacted the AppNotificationSettings, which has no plan
to be migrated.

Bug: 236346018
Test: Unit test
Test: Manual with Settings App
Change-Id: I4ae669ce36eb6ab73f1adf99585f424e03bf90fb