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/update_engine.te b/private/update_engine.te
index e4e7009..a76ab49 100644
--- a/private/update_engine.te
+++ b/private/update_engine.te
@@ -5,3 +5,9 @@
 # Allow to talk to gsid.
 allow update_engine gsi_service:service_manager find;
 binder_call(update_engine, gsid)
+
+# Allow to start gsid service.
+set_prop(update_engine, ctl_gsid_prop)
+
+# Allow to set the OTA related properties, e.g. ota.warm_reset.
+set_prop(update_engine, ota_prop)