Store phone blacklist in content provider (2/4)

Change-Id: I0fe685ff0a63848d666fc76510e4a331b74b94fe
telephony: Add support for choosing a default APN

 * Sometimes, the standard method of choosing the "first" available APN
   is not what we want. Consider the case where a certain provider has
   both a "normal" APN and an LTE APN. The LTE APN is what we want, but
   it's not chosen.
 * Add a new overlayable value "config_preferred_apn" to handle this. A
   device can override this. The format is "apn,mcc,mnc".

Change-Id: Ia6ca4159491bee15b3f18ad7ad524b8b0ffce2f2
TelephonyProvider: Handle database upgrade for MSIM

* need to add a boolean field 'preferred' to the carrier table in telephony.db

Change-Id: I9cf2c5bcebd7e7c3aca90f7e2a246b9d85d01c76
Improve delete handling code.

Change-Id: I3f09f00a2966ee246056ea11ec55d952da6aabc0
Drop blacklist number uniqueness constraint.

It's very hard to deal with that constraint in practise, so drop the
contraint from the DB and handle potential duplicate rows when querying.

Change-Id: Id28a415ba80cf100879b24de88b4b50638e900ca
TelephonyProvider: Update Icons to KitKat

* These are residuals from Jellybean.  This is KitKat!!!

Change-Id: I4bd5e013b072daab3433e7d852ac4c4027a29a7d