Set notification listener defaults for system VrListeners.

- For a package that has been enabled as a VrListenerService
  and been preinstalled on the device's system image, enable
  NotificationListenerServices by default for that package as
  well.
- Use appops function instead of packagemanager for runtime
  permissions.

Bug: 28614768
Change-Id: If88d47b666656a6e9567118626c1d9fa00280ec4