Record Call's Via Number in Call Extras to CallLog

Add a column to the CallLog Backup that records the secondary line
number that an incoming call has been received on. More specifically, a
call is assumed to be considered a "VIA number" if the call's incoming
line number does not match the number registered with the SIM card.

BUG: 25594198

Change-Id: I1bdc949fcee836945eec905b6a0afeec52b4ca29