Allow system_server to read sepolicy from sysfs

Bug: 308471499
Test: let system server hash the policy
Change-Id: I8fc171e25636698d787be029c00471e0768f4c7a
diff --git a/private/system_server.te b/private/system_server.te
index f9627e3..4801969 100644
--- a/private/system_server.te
+++ b/private/system_server.te
@@ -927,6 +927,9 @@
 allow system_server sysfs_zram:dir search;
 allow system_server sysfs_zram:file rw_file_perms;
 
+# Read /sys/fs/selinux/policy
+allow system_server kernel:security read_policy;
+
 add_service(system_server, system_server_service);
 allow system_server artd_service:service_manager find;
 allow system_server audioserver_service:service_manager find;