system_server: bring back sdcard_type neverallow rule

We had disabled the neverallow rule when system_server was
in permissive_or_unconfined(), but forgot to reenable it.
Now that system_server is in enforcing/confined, bring it
back.

Change-Id: I6f74793d4889e3da783361c4d488b25f804ac8ba
1 file changed