How to set inifinite DHCP lease time in the OVN on openstack

Issue

• The lease time of the DHCP in the OVN was seted default value with "43200".

# ovn-nbctl list DHCP_Options
_uuid               : abcd1234-1234-1234-abcd-1234abcd1232
...
options             : {classless_static_route="{169.254.169.254/32,14.32.72.126, 0.0.0.0/0,14.32.72.254}", dns_server="{147.6.44.45, 147.6.44.44}", lease_time="43200", mtu="1500", router="14.32.72.254", server_id="14.32.72.254", server_mac="ab:cd:ef:12:34:56"}
_uuid               : abcd1234-1234-1234-abcd-1234abcd1234
...
options             : {classless_static_route="{169.254.169.254/32,172.23.154.11}", dns_server="{147.6.44.44, 147.6.44.45}", lease_time="43200", mtu="1500", server_id="172.23.154.11", server_mac="ab:cd:ef:11:22:33"}