Bug 1070050 - Highlight phone numbers on contacts buttons that are close matches of call log entries. r=Rik

There are already tests for this here:
https://github.com/DouglasSherk/gaia/blob/1070050-dialer-contacts-buttons-highlighting/apps/communications/dialer/test/unit/call_info_test.js#L253
and here:
https://github.com/DouglasSherk/gaia/blob/1070050-dialer-contacts-buttons-highlighting/apps/communications/dialer/test/unit/call_info_test.js#L266