Fix looking up of contacts for SIP calls.

Currently, for a SIP call we only look up whether there is a matching
SIP address on one of the contacts.

However, it is also possible to receive calls from regular phone numbers
on a SIP account, e.g., if there is a incoming calls number associated
with the account.

In those cases, the SIP address of the caller is of the form
<number>@<domain>.

This commit changes the look-up code for SIP calls in the call log to
fall back to looking up the <number> part of a SIP address if there is
not a match within the SIP addresses of contacts.

This is in line with what is already done for incoming and outgoing
calls placed via SIP to regular phone number.

Bug: 5390366
Change-Id: I98b359eee08a943f9cef719390bb8dcb4da09b67