sepolicy: give otapreopt getattr

(cherry picked from commit 88c51465)

Allow the otapreopt rename script to read file attributes. This is
being used to print the aggregate artifact size for diagnostic
purposes.

Bug: 30832951
Change-Id: Iee410adf59dcbb74fa4b49edb27d028025cd8bf9

otapreopt_slot.te

@@ -11,8 +11,9 @@ type otapreopt_slot_exec, exec_type, file_type;
 init_daemon_domain(otapreopt_slot)
 
 # The otapreopt_slot renames the OTA dalvik-cache to the regular dalvik-cache, and cleans up
-# the directory afterwards.
+# the directory afterwards. For logging of aggregate size, we need getattr.
 allow otapreopt_slot ota_data_file:dir { rw_dir_perms rename reparent rmdir };
+allow otapreopt_slot ota_data_file:file { getattr };
 
 # Delete old content of the dalvik-cache.
 allow otapreopt_slot dalvikcache_data_file:dir { add_name getattr open read remove_name rmdir search write };