Add initial preferred APN feature

In multi-sim scenarios, each sim will have its own preferred APN
setting. When ApnSettings sets/reads the preferred Apn, SUB id will
be passed to TelephonyProvider.  TelephonyProvider will update/return
the value of the key 'apn-id0' or 'apn-id1' based on the given SUB id.

Change-Id: Ifbbb49f2b38a5c6cff56785313a80a34479ea08f
Telephony: Disable PIN Toggle option if SIM is in Locked state.

When user presses cancel in PIN lock screen, card will be in
LOCKED state and hence cannot access SIM for any transactions.

So Disable PIN Toggle option in Locked State.

Change-Id: Id569c9976c6fb9a3b2490577c80348cf2f2489ab
CRs-Fixed: 576782