Revert "Migrate to upstream policy version 30"

This reverts commit 2ea23a6e1ade883ba81f58b364109c4da94ba584.

Change-Id: I5e9efa56d74ab22030611cab515e050e0bb77aca
diff --git a/Android.mk b/Android.mk
index 91d6303..102b2b1 100644
--- a/Android.mk
+++ b/Android.mk
@@ -5,7 +5,7 @@
 # SELinux policy version.
 # Must be <= /sys/fs/selinux/policyvers reported by the Android kernel.
 # Must be within the compatibility range reported by checkpolicy -V.
-POLICYVERS ?= 30
+POLICYVERS ?= 29
 
 MLS_SENS=1
 MLS_CATS=1024