Stop using puppet to configure VIPs in /etc/hosts

Stop using puppet to configure VIPs in /etc/hosts

This patch drops use of the vip-hosts.yaml service which can
cause issues during deployment because puppet 'hosts' resources
overwrite the data in /etc/hosts. The only reason things seem to work
at all at the moment is because our hosts element in t-i-e runs
on each os-refresh-config iteration and re-adds the dropped hosts
entries.

To work around the issue we add a conditional which selectively
adds the extra hosts entries only if the AddVipsToEtcHosts is set
to true.

Closes-bug: 1645123

Change-Id: Ic6aaeb249a127df83894f32a704219683a6382b2