Pass '--dhcp-authoritative' option to dnsmasq

Pass '--dhcp-authoritative' option to dnsmasq

When dnsmasq is restarted, it forgets about all leases (since it runs
with leasefile-ro option). When client tries to renew its lease, dnsmasq
sends DHCPNAK reply with message "lease not found". Then client shuts
down the network and re-request lease from DHCP server (and gets exactly
same IP address). There's a small network downtime which affects
services, like zookeeper, running in VMs.

Change-Id: Ieff0236670c1403b5d79ad8e50d7574c1b694e34
Closes-Bug: #1345947