The ceilometer-upgrade command needs to be run to update back end
ceilometer data stores. When attempting to run this command during
deploy time due to the number of required relations many inherent
race conditions exist leading to Bug#1749280.

This change allows the ceilometer-upgrade command to be run as an action
post-deploy.

Change-Id: I64a56d9a38532476b8a01df6227231a1276c708f
Closes-Bug: #1749280