While I8bb398e299aa68147004723a18d3a1ec459011e5 stopped setting
the net.ipv4.ip_forward sysctl, this change explicitly removes the
option from the Kolla sysctl config file. In the absence of another
source for this sysctl, it should revert to the default of 0 after the
next reboot.
A deployer looking to more aggressively change the value may set
neutron_l3_agent_host_ipv4_ip_forward to 0. Any deployments still
relying on the previous value may set
neutron_l3_agent_host_ipv4_ip_forward to 1.
Related-Bug: #1945453
Change-Id: I9b39307ad8d6c51e215fe3d3bc56aab998d218ec