Improve multi SIM support of SmsNumberUtils

SmsNumberUtils is special for Verizon requirement, it handles MO SMS assist dialing.
This feature is enabled by Verizon MCCMNC of the default SIM, it's a problem for a
multi-SIM device.

Test: make & manual test
Bug: 112825352
Change-Id: I31723ec07b092553e7d93d5f8287e32111d58fa3