* Updates etcd to v3.4
* Updated the config to use v3.4's logging mechanism
* Deprecated etcd CA parameters aren't used, so we are not affected
by their removal.
* Note that we are not currently guarding against skip-version updates for
etcd.
Notable non-voting jobs exercising some of this:
* kolla-ansible-ubuntu-upgrade-cephadm (cinder->tooz->etcd3gw->etcd)
* kolla-ansible-ubuntu-zun (see
https://review.opendev.org/c/openstack/openstack-ansible/+/883194 )
Depends-On: https://review.opendev.org/c/openstack/kolla/+/890464
Change-Id: I086e7bbc7db64421445731a533265e7056fbdb43