Strengthen setenforce and setbool assertions

Change-Id: I58f15889c248b49f9e29028a3c0a86b4c950ff07

assert.te

@@ -16,7 +16,7 @@ neverallow appdomain kmem_device:chr_file { read write };
 
 # Setting SELinux enforcing status or booleans.
 # Conditionally allowed to system_app for SEAndroidManager.
-neverallow { appdomain -system_app } kernel:security { setenforce setbool };
+neverallow { domain -unconfineddomain -system -system_app } kernel:security { setenforce setbool };
 
 # Load security policy.
 neverallow appdomain kernel:security load_policy;