Bug 995630 - Remove Gaia code that supported the old mozTelephony.dial/dialEmergency API

- Removed requireApp usage
- Moved the telephony.dial/dialEmergency stubbing to the main suite
- Some modifications for jshint compat
Merge pull request #18258 from Rik/remove-non-promise-995630

Bug 995630 - Remove Gaia code that supported the old mozTelephony.dial/d... r=etienne