Look up OS_PROJECT_NAME for OpenStack project name (#6262)

On OpenStack history, we used to call "tenant" for separeted namespace.
However we use "project" now instead.
Then we have replaced "tenant" with "project". Then all "TENANT" variables
also are renamed to "PROJECT".
This makes Kubespray search "PROJECT" variable also for newer OpenStack
clouds.

roles/kubernetes-apps/external_cloud_controller/openstack/defaults/main.yml

@@ -7,7 +7,7 @@ external_openstack_username: "{{ lookup('env','OS_USERNAME')  }}"
 external_openstack_password: "{{ lookup('env','OS_PASSWORD')  }}"
 external_openstack_region: "{{ lookup('env','OS_REGION_NAME')  }}"
 external_openstack_tenant_id: "{{ lookup('env','OS_TENANT_ID')| default(lookup('env','OS_PROJECT_ID'),true) }}"
-external_openstack_tenant_name: "{{ lookup('env','OS_TENANT_NAME') }}"
+external_openstack_tenant_name: "{{ lookup('env','OS_TENANT_NAME')| default(lookup('env','OS_PROJECT_NAME'),true) }}"
 external_openstack_domain_name: "{{ lookup('env','OS_USER_DOMAIN_NAME') }}"
 external_openstack_domain_id: "{{ lookup('env','OS_USER_DOMAIN_ID') }}"
 external_openstack_cacert: "{{ lookup('env','OS_CACERT') }}"