Move system property rules to private

public/property split is landed to selectively export public types to
vendors. So rules happening within system should be in private. This
introduces private/property.te and moves all allow and neverallow rules
from any coredomains to system defiend properties.

Bug: 150331497
Test: system/sepolicy/tools/build_policies.sh
Change-Id: I0d929024ae9f4ae3830d4bf3d59e999febb22cbe
Merged-In: I0d929024ae9f4ae3830d4bf3d59e999febb22cbe
(cherry picked from commit 42c7d8966cc5f76c84c001c5af787cbfade736c8)
diff --git a/private/lmkd.te b/private/lmkd.te
index a07ce87..7246051 100644
--- a/private/lmkd.te
+++ b/private/lmkd.te
@@ -1,3 +1,6 @@
 typeattribute lmkd coredomain;
 
 init_daemon_domain(lmkd)
+
+# Set sys.lmk.* properties.
+set_prop(lmkd, system_lmk_prop)