Bug 938557 - Write a test for finding a contact using the dialer

--Initial description--
!!!Please do not review this yet!!!
This pull was made as a reduced testcase for a marionette bug.
As soon as [bug 939108](https://bugzilla.mozilla.org/show_bug.cgi?id=939108) is fixed, this will be unblocked and I will update it accordingly

--Current Status--
[bug 939108](https://bugzilla.mozilla.org/show_bug.cgi?id=939108) is RWFM, so this pull is awaiting your reviews.