sepolicy: Fix MTP for sdcardfs

Change-Id: I8fe011140798925ee5b5926355868febd595a788
diff --git a/sepolicy/kernel.te b/sepolicy/kernel.te
index b944a75..2984b77 100644
--- a/sepolicy/kernel.te
+++ b/sepolicy/kernel.te
@@ -1,2 +1,3 @@
 # used by sdcardfs to read package list
 allow kernel system_data_file:file open;
+allow kernel media_rw_data_file:file rw_file_perms;