Revert "Restore system_server ioctl socket access."

The underlying ioctl denial was fixed in device-specific policy.
It's not needed in core policy.

A search of SELinux denials shows no reported denials, other than the
ones showing up on marlin.

This reverts commit ec3285cd.

Test: AndroiTS GPS Test app shows GPS data, no SELinux denials.
Bug: 32290392
Change-Id: I1ba7bad43a2cdd7cdebbe1c8543a71eee765621d

public/domain.te

@@ -175,7 +175,7 @@ allowxperm domain domain:{ unix_dgram_socket unix_stream_socket }
 ###
 
 # All socket ioctls must be restricted to a whitelist.
-neverallowxperm { domain -system_server } domain:socket_class_set ioctl { 0 };
+neverallowxperm domain domain:socket_class_set ioctl { 0 };
 
 # Do not allow any domain other than init or recovery to create unlabeled files.
 neverallow { domain -init -recovery } unlabeled:dir_file_class_set create;

public/system_server.te

@@ -81,7 +81,7 @@ allow system_server self:netlink_generic_socket create_socket_perms_no_ioctl;
 # to the kernel. The ioctl permission is specifically omitted here, but may
 # be added to device specific policy along with the ioctl commands to be
 # whitelisted.
-allow system_server self:socket create_socket_perms;
+allow system_server self:socket create_socket_perms_no_ioctl;
 
 # Set and get routes directly via netlink.
 allow system_server self:netlink_route_socket nlmsg_write;