Telephony: Make sure we're stripping non-digits prior checkDestination.

  If we don't strip non-digits from the destination number, we'll fail
  to be triggered as an SMS short code and we'll go through the
  broadcast queue for UiccSmsController prior to being sent out.

Change-Id: I87157c049dc410d3ed46d0ea4e21c4ddcbb070d9
TICKET: CYNGNOS-921
(cherry picked from commit 9319b2d1)