Bug 867948 - Ensure findByPhoneNumber callback checks their values

This is legitimate (and it seems meaningfull) for findByPhoneNumber to
return either null or empty array, depending on the case. However, we
must ensure to properly check for those returns values, otherwise we
might blow up in the air.
Revert "Bug 876757 - [contacts] Import connectors UI looks too big"

This reverts commit 7f371eccd2dbbcd00a6e3c3019e75cd16c2e5ecf.
Bug 877095 - [contacts] Missplaced import switches