Make the mediaserver domain enforcing.

Change-Id: Ib693b563c2db6abc02cf7dbeb12ed61c09734fa8
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>

mediaserver.te

 # mediaserver - multimedia daemon
 type mediaserver, domain;
-permissive_or_unconfined(mediaserver)
 type mediaserver_exec, exec_type, file_type;
 
 typeattribute mediaserver mlstrustedsubject;