Remove ceilometer service overrides

devstack no longer installs ceilometer services unlesss ceilometer
devstack plugin is enabled, so we can safely remove the options to
disable ceilometer services.

This allows us to remove references to removed services such as
ceilometer-api .

Change-Id: I4201878d0deba4490cf2a08bbabec8fe64474385

Author: kajinamit

.zuul.yaml

@@ -86,13 +86,6 @@
         # NOTE(amotoki): Some neutron features are enabled by devstack plugin
         neutron: https://opendev.org/openstack/neutron
       devstack_services:
-        ceilometer-acentral: false
-        ceilometer-acompute: false
-        ceilometer-alarm-evaluator: false
-        ceilometer-alarm-notifier: false
-        ceilometer-anotification: false
-        ceilometer-api: false
-        ceilometer-collector: false
         s-account: true
         s-container: true
         s-object: true