Switch gnocchi service name to service

Previously we used different from other services project name to protect
swift from looping. However nowadays ceilometer middleware does
exclude service project by default. So no futher actions needed
unless deployer want to measure service project excluding gnocchi
In this scenario, deployer still can define custom
`gnocchi_service_project_name` in their user_variables.

Depends-On: https://review.opendev.org/c/openstack/openstack-ansible-galera_server/+/791107
Change-Id: Ic0ffa6908bfc55ffdb41ea9b8e7435e4dc88ddca
Related-Bug: #1879192

defaults/main.yml

@@ -101,7 +101,7 @@ gnocchi_keystone_auth_type: password
 gnocchi_service_region: "{{ service_region | default('RegionOne') }}"
 gnocchi_service_user_name: gnocchi
 gnocchi_role_name: admin
-gnocchi_service_project_name: "{{ (gnocchi_storage_driver == 'swift') | ternary('gnocchi_swift', 'service') }}"
+gnocchi_service_project_name: service
 gnocchi_service_project_domain_id: default
 gnocchi_service_user_domain_id: default
 gnocchi_service_address: "{{ openstack_service_bind_address | default('0.0.0.0') }}"

releasenotes/notes/gnocchi_project_name-41f74bdb17c219f8.yaml

@@ -0,0 +1,8 @@
+---
+upgrade:
+  - |
+    ``gnocchi_service_project_name`` now set by to ``service`` even for
+    deployments involving Swift. Nowadays cielometer.middleware exclude
+    ``service`` project by default, so no additional protection is required.
+    In case you want to preserve current ``gnocchi_service_project_name``,
+    define it equal to ``gnocchi_swift`` in your user_variables.yml

templates/gnocchi.conf.j2

@@ -63,7 +63,7 @@ swift_key: "{{ gnocchi_service_password }}"
 swift_region_name: "{{ gnocchi_service_region }}"
 swift_project_domain_id: "{{ gnocchi_service_project_domain_id }}"
 swift_user_domain_id: "{{ gnocchi_service_user_domain_id }}"
-swift_tenant_name: "{{ gnocchi_service_project_name }}"
+swift_project_name: "{{ gnocchi_service_project_name }}"
 swift_container_prefix: gnocchi
 {% endif %}
 {% if gnocchi_storage_driver == 'ceph' %}