Fixed that setup wizard sometimes report en-GB as default language.

The incorrect language was caused by the incorrect MCC/MNC reported
by CSIM application. Fixed by retrieving the correct MCC/MNC from the 
telephony manager public API, which internall pulls out the correct
MCC/MNC from the USIM application.

bug: 26963170
Change-Id: I7a2f9fc7761364f52c2caa1668d4086ede9d210d