telephony: Also override nw mode on creation of phone objects.

  The CAF change @ 8ad9463f allows
  overriding of the preferred nw mode at the creation of the phone
  object based upon the phone id. Since we abstract this to another
  layer where we have user preferred nw type, we need to override this
  as well.

Change-Id: Id65c095584aba97112a3318cc922d7e0107c12da