rild: Remove toolbox_exec perms

Confirmed via audit logs that it is not required.

Change-Id: I01d4b7ec15d4c852a9f28daf0b40ab4bce930125

rild.te

@@ -23,9 +23,6 @@ allow rild sdcard_type:dir r_dir_perms;
 allow rild system_data_file:dir r_dir_perms;
 allow rild system_data_file:file r_file_perms;
 allow rild system_file:file x_file_perms;
-# XXX Run toolbox.  Might not be needed.
-allow rild toolbox_exec:file rx_file_perms;
-auditallow rild toolbox_exec:file rx_file_perms;
 
 # property service
 set_prop(rild, radio_prop)