Description of problem:
CeilometerStoreEvents defaults to off but events are still saved to mongodb.  This causes mongodb to grow in size until the disk runs out because the event TTL is set to -1.  store_events doesn't matter because events_dispatcher=database is configured by default thus causing events to be saved into mongodb without any ttl.


Version-Release number of selected component (if applicable):
OSP10 - Newton GA build

How reproducible:
Always

Steps to Reproduce:
1. Deploy according to docs and view size of the event collection in mongodb
2.
3.

Actual results:
the event collection will grow in size as ceilometer stores events

Expected results:
If CeilometerStoreEvents is set to false, events should not be stored.  


Additional info:
CeilometerStoreEvents set to false [0]
CeilometerStoreEvents maps to store_events under agent notification configuration [1]
events_dispatcher defaults to database in ceilometer puppet installer [2]
event_time_to_live defaults to -1 in ceilometer puppet installer [3]


This is due to CeilometerStoreEvents maps to store_events under agent_notification configuration section.

[0] https://github.com/openstack/tripleo-heat-templates/blob/stable/newton/puppet/services/ceilometer-base.yaml#L43
[1] https://github.com/openstack/tripleo-heat-templates/blob/stable/newton/puppet/services/ceilometer-base.yaml#L100
[2] https://github.com/openstack/puppet-ceilometer/blob/stable/newton/manifests/collector.pp#L50
[3] https://github.com/openstack/puppet-ceilometer/blob/fc4a0fd5100128280703dbb3f8e109fb9393a2d0/manifests/init.pp#L235

There is likely some parameters we can pass into the deploy command to mitigate this issue.