Use service tenant for ceilometer
Use service tenant for ceilometer

Configure ceilometer to use the service tenant instead of the admin
tenant.  Using the admin tenant is not required and a security risk.

This brings the ceilometer configuration in line with the
recommendations from the official installation guide:
http://docs.openstack.org/kilo/install-guide/install/yum/content/ceilometer-controller-install.html

Change-Id: Ia14695eb23a1ff551fd27f74b4cb864e80b100e3
Partial-Bug: #1358237

dprince/tripleo-heat-templates,trozet/opnfv-tht,bcrochet/tripleo-heat-templates,openstack/tripleo-heat-templates,trozet/opnfv-tht,openstack/tripleo-heat-templates,bcrochet/tripleo-heat-templates,dprince/tripleo-heat-templates,bcrochet/tripleo-heat-templates,trozet/opnfv-tht