make NUMERIC field null in case mcc/mnc is not defined

NUMERIC is not set to null in database in case mcc/mnc
is not defined in apns-conf.xml file.
This happens because it is a result of concaternating
two null strings mcc/mnc.

Test: Manual
Bug: 197452795
Change-Id: Iaf617c989c536262710b8410606161e4fe2291dd
1 file changed