apns: sprint: Default to legacy n.*, allow x.* as an alternative

* Newer Sprint devices will only get LTE on the x.* variant of
  the APN. Though, using this breaks all legacy Sprint devices
  LTE connection. until we have a majority of post 8996 era
  devices, default to the n.* variant of the APN.

Change-Id: I95a26a5d3175dbf6ebd4eb78e9f2720017c8c7e2
1 file changed