Generate random keystone users

Depends-On: https://gerrit.mcp.mirantis.com/#/c/44319/
Depends-On: https://gerrit.mcp.mirantis.com/#/c/45118/
Depends-On: https://gerrit.mcp.mirantis.com/#/c/45119/

Related-Prod: PROD-29868
Related-Prod: PROD-31315
(cherry picked from commit f5956c2f6151cc5d99659103f90641ea66eac44a)
(cherry picked from commit 70dd0f0587eb297fbefdea43837839c4983b8378)

Change-Id: I402be73437d5397224184a4fd71e2f6abae24db2
diff --git a/gnocchi/common/cluster.yml b/gnocchi/common/cluster.yml
index b00ffa5..e1c58da 100644
--- a/gnocchi/common/cluster.yml
+++ b/gnocchi/common/cluster.yml
@@ -6,6 +6,8 @@
   gnocchi:
     common:
       database:
+        user: ${_param:mysql_gnocchi_username}
+        password: ${_param:mysql_gnocchi_password}
         x509:
           enabled: ${_param:openstack_mysql_x509_enabled}
           ca_file: ${_param:mysql_gnocchi_ssl_ca_file}
diff --git a/gnocchi/common/single.yml b/gnocchi/common/single.yml
index 834db2f..614e85e 100644
--- a/gnocchi/common/single.yml
+++ b/gnocchi/common/single.yml
@@ -6,6 +6,8 @@
   gnocchi:
     common:
       database:
+        user: ${_param:mysql_gnocchi_username}
+        password: ${_param:mysql_gnocchi_password}
         x509:
           enabled: ${_param:openstack_mysql_x509_enabled}
           ca_file: ${_param:mysql_gnocchi_ssl_ca_file}
diff --git a/gnocchi/server/cluster.yml b/gnocchi/server/cluster.yml
index 1ad5e44..8e3265e 100644
--- a/gnocchi/server/cluster.yml
+++ b/gnocchi/server/cluster.yml
@@ -17,6 +17,8 @@
         metric_processing_delay: 15
         metric_reporting_delay: 30
       identity:
+        user: ${_param:keystone_gnocchi_username}
+        password: ${_param:keystone_gnocchi_password}
         host: ${_param:openstack_control_address}
         region: ${_param:openstack_region}
         protocol: ${_param:cluster_internal_protocol}
diff --git a/gnocchi/server/single.yml b/gnocchi/server/single.yml
index 43a2c9d..cf6ebfa 100644
--- a/gnocchi/server/single.yml
+++ b/gnocchi/server/single.yml
@@ -5,6 +5,8 @@
     server:
       role: ${_param:openstack_node_role}
       identity:
+        user: ${_param:keystone_gnocchi_username}
+        password: ${_param:keystone_gnocchi_password}
         region: ${_param:openstack_region}
         protocol: ${_param:internal_protocol}
       metricd: