Add missing comment from my previous merge in 47966cec.

Test: Built.
Change-Id: Ia5f5b52e10e9411cd87901053675d9e77a622529

private/file_contexts

@@ -450,6 +450,7 @@
 # LocalTransport (backup) uses this subtree
 /data/cache/backup(/.*)?	u:object_r:cache_private_backup_file:s0
 
+#############################
 # asec containers
 /mnt/asec(/.*)?             u:object_r:asec_apk_file:s0
 /mnt/asec/[^/]+/[^/]+\.zip  u:object_r:asec_public_file:s0