shell.te: Allow read access to system_file

am: 29b9532a

* commit '29b9532a':
  shell.te: Allow read access to system_file

shell.te

@@ -52,6 +52,7 @@ allow shell tty_device:chr_file rw_file_perms;
 allow shell console_device:chr_file rw_file_perms;
 allow shell input_device:dir r_dir_perms;
 allow shell input_device:chr_file rw_file_perms;
+r_dir_file(shell, system_file)
 allow shell system_file:file x_file_perms;
 allow shell toolbox_exec:file rx_file_perms;
 allow shell shell_exec:file rx_file_perms;