Kill spn-conf overrides

These were overloading the ASCII names to region-specific charsets,
which looks nice but it's horribly confusing if you're not native
from those regions and happen to be roaming there.

So... like our upstreams, just show the original carrier names

Change-Id: Icb3c6c9be2a4ee57866f2f57411a4f441be88f7c