Add getNetworkSpecifier() and getCarrierConfig()

This allows making network request and getting carrier config on a
specfic SIM.

Bug: 32414216
Test: cts-tradefed run cts-dev --module CtsTelephonyTestCases
Merged-In: Id52688d73b74bc55ee2da71a22454957fdd7b57b
Change-Id: Iebe2d883e193afdde13303d76014dfd7f4fb06dd
4 files changed