Store correct IMSI when retreived from SIMRecords and use it for RuimRecords

Verizon does weird things regarding SIMRecords vs. RuimRecords.
This will store the IMSI gathered with SIMRecords for use when RuimRecords
wants to get the APN/operator number.

Set System prop "ro.telephony.get_imsi_from_sim=true" to enable this function

Change-Id: I7df5d3c721afa3eeaf2f077b9f7399bd027d448b