Improve callstats number matching code.

Make it a little more efficient, and make sure the ContactInfo and
CallStatsDetails instances always stay in sync.

Change-Id: I0b01e6fc036ce70dccbccf1d9002843331304d50
[2/2] Dialer: Add a non-intrusive dialoger for incoming calls

Change-Id: Ibbb9653b4a1da12fe3a7ad8f98ecbb8bffb13311