Prevent guest user from toggling mobile data Quick Setting

Prevents the guest user from toggling mobile data on/off by using the
mobile data quick setting.

The guest user is not able to access the network settings menu where
mobile data is usually toggled. The guest user should therefore not be
able to toggle mobile data on/off by using quick settings.

Bug: 150262422
Test: atest SystemUITests
Change-Id: I24262d4580fa5d7414d5d3e7e0e42873432ab74f