init: drop read_policy permission

As of https://android-review.googlesource.com/127858 ,
open(O_RDONLY) is no longer used for chmod. It's no
longer necessary to allow init to read the SELinux policy.

Change-Id: I691dd220827a01a8d7a9955b62f8aca50eb25447

init.te

@@ -115,9 +115,6 @@ allow init kernel:security load_policy;
 allow init kernel:system syslog_mod;
 allow init self:capability2 syslog;
 
-# Triggered by chmod 0444 /sys/fs/selinux/policy.
-allow init kernel:security read_policy;
-
 # Set usermodehelpers and /proc security settings.
 allow init usermodehelper:file rw_file_perms;
 allow init proc_security:file rw_file_perms;