VRRP healthchecks were enabled by default starting in the 19.07 charm
release for network deployments which utilize l3ha or dvr+snat. The VRRP
healthchecks have specific expectations that may not be satisfied in
various data centers. This leads to problems with networks as failed
healthchecks lead to router failovers.
This change alters the default config option to disable the vrrp
healthchecks by default and require users to opt in to using them. The
description around the option has been updated to indicate that doing so
may lead to routers failing over if ICMP pings are missed.
Closes-Bug: #192101
Change-Id: Ie0ebb8072fa802dc8c2478a0b3ca38202d49c85f