Enable gnocchi systemd services

Enable gnocchi systemd services

Marian Krcmari noticed that on a freshly deployed HA Newton system
gnocchi-metricd and gnocchi-statsd are down. This likely came about when
gnocchi moved to composable roles
(I40a3815923099d00a0f3fc1d88a942784e7c6fb9) and those settings made
sense when it was managed by pacemaker.

Also make sure that all services are disabled when managed via
pacemaker and add manage_service: false for gnocchi-api for pacemaker
which was missing.

Change-Id: If7d681e0fa3e84379ac83c8a55b481369fe2849e