Allow importing contacts from mulitple sims

There are multiple options we may need to display under Import/Export
for SIM cards

1. If only one sim card, display "Import from SIM" option

2. If multiple SIMs, display "Import from SIM, <name> - <phone-number>
for each sim subscription.

3. If a sim subscription doesn't have a known phone number, display
"Import from SIM, <name>" for the sim subscription.

Bug: 16525652
Change-Id: I73b3c45be116c75d597727f4b31ccf2d0e61c623