sepolicy: allow settings to read selinux status

Change-Id: I218433da3c257a80ad4cd63230c8040292123804
diff --git a/common/private/system_app.te b/common/private/system_app.te
index c4fe514..2e590de 100644
--- a/common/private/system_app.te
+++ b/common/private/system_app.te
@@ -8,3 +8,6 @@
 
 # Allow SetupWizard to set recovery update prop
 set_prop(system_app, recovery_update_prop)
+
+# Read selinux status
+allow system_app selinuxfs:file r_file_perms;