Generate random keystone users

Change-Id: I8dbd07b10d29b43d1c35fa76bcaa0f0efb32beda
Related-Prod: PROD-29868
diff --git a/mysql/client/database_upgrade/nova_api.yml b/mysql/client/database_upgrade/nova_api.yml
index 8bb33c8..d9815d5 100644
--- a/mysql/client/database_upgrade/nova_api.yml
+++ b/mysql/client/database_upgrade/nova_api.yml
@@ -7,11 +7,11 @@
             nova_upgrade_api:
               encoding: utf8
               users:
-              - name: nova
+              - name: ${_param:mysql_nova_username}
                 password: ${_param:mysql_nova_password}
                 host: '%'
                 rights: all
-              - name: nova
+              - name: ${_param:mysql_nova_username}
                 password: ${_param:mysql_nova_password}
                 host: ${_param:single_address}
                 rights: all
@@ -23,11 +23,11 @@
             nova_upgrade_cell0:
               encoding: utf8
               users:
-              - name: nova
+              - name: ${_param:mysql_nova_username}
                 password: ${_param:mysql_nova_password}
                 host: '%'
                 rights: all
-              - name: nova
+              - name: ${_param:mysql_nova_username}
                 password: ${_param:mysql_nova_password}
                 host: ${_param:single_address}
                 rights: all