Make system_app enforcing.

Change-Id: I9c3ff0a79d947a14084638772451d06298c43e47
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
diff --git a/system_app.te b/system_app.te
index 05f1b6c..42f7f7e 100644
--- a/system_app.te
+++ b/system_app.te
@@ -4,7 +4,6 @@
 # server.
 #
 type system_app, domain;
-permissive_or_unconfined(system_app)
 app_domain(system_app)
 net_domain(system_app)
 binder_service(system_app)