cm: add sepolicy entry for lockscreen wallpaper

Change-Id: Ie779392ab8118d192873a01ec5c7de3e5938ed17
Signed-off-by: Roman Birg <roman@cyngn.com>
diff --git a/sepolicy/file_contexts b/sepolicy/file_contexts
index 902831b..c179f1e 100644
--- a/sepolicy/file_contexts
+++ b/sepolicy/file_contexts
@@ -25,3 +25,6 @@
 
 # Expansion of these hooks is a bit unconventional
 /cache/com.cyanogenmod.keyhandler.dex   u:object_r:dalvikcache_data_file:s0
+
+# Lockscreen wallpaper
+/data/system/users/[0-9]+/keyguard_wallpaper   u:object_r:wallpaper_file:s0