Do not change voicemail calls to voicemail: uri automatically

Previous change (Change-Id: Iaca971a195144a16f7853e3555375922ad54b81b)
performed some code cleanup/restructuring which caused all calls from
Dialtacts to any voicemail number to be sent as a "voicemail:" CALL
Intent instead of a "tel:" CALL Intent.  That change lost post-dial
digits in the process.

This change undoes the portion of that change which translated all
"tel:" calls to voicemail numbers into "voicemail:" calls.

Confirmed that this change does not alter the functionality of a voicemail
call and continues to display the i18n'ed "Voice Mail" string in the
incall screen/dialpad.

bug: 6969236
Change-Id: I41ba17e419e3189a73f8032399deaa78febd525c