Allow system_server to hard link its own files

am: d9b0a34a

* commit 'd9b0a34a':
  Allow system_server to hard link its own files

Change-Id: I44056867fd9d4881396020ba110cb5750fc3c71f

system_server.te

@@ -292,6 +292,8 @@ allow system_server system_data_file:file relabelfrom;
 allow system_server wallpaper_file:file relabelto;
 allow system_server wallpaper_file:file { rw_file_perms unlink };
 
+# Backup of wallpaper imagery uses temporary hard links to avoid data churn
+allow system_server { system_data_file wallpaper_file }:file link;
 
 # ShortcutManager icons
 allow system_server system_data_file:dir relabelfrom;