Fix apn population in cdma

DcTracker uses getOperatorNumeric method to read
operator numeric value from sim/ruim records to query apns
from telephony db. For RuimRecords the operator numeric
method is defined as getRUIMOperatorNumeric instead of
extending abstract method getOperatorNumeric declared in
IccRecords. Rename getRUIMOperatorNumeric to getOperatorNumeric
such that DcTracker can use same method to read operator numeric
from sim/ruim records

Change-Id: I2d3ae4cdfed9cafb8f4f6f77ccbcf1410c2c4862
CRs-Fixed: 731653