Explicitly allow netd to take the iptables lock.

This was previously relying on domain_deprecated rules deleted in
change I588a1e7ea7ef984907b79a5a391efb2dcd6e6431.

Bug: 28760354
Test: unbreaks networking on AOSP bullhead
Change-Id: I873e1f08f72104dee7509e45b1db0b284ca56085
1 file changed