CellSettings: Fix Carrier settings removal for GSM

The 'Carrier settings' menu should be removed if
config_carrier_settings_enable is set to false, regardless of whether
csp_enabled is true.

Change-Id: Id71e47acf215234b9f8f9a5dcec687d39856bf7c

Patchset: 1
http://review.cyanogenmod.org/#/c/81607/