Add defaults for dashboard container image params

This patch adds default values for container images of
dashabord services.

roles/cifmw_cephadm/defaults/main.yml

@@ -97,3 +97,8 @@ cifmw_cephadm_grafana_admin_user: 'admin'
 cifmw_cephadm_grafana_admin_password: '/home/grafana_password.yml'
 cifmw_cephadm_prometheus_port: 9092
 cifmw_cephadm_grafana_port: 3100
+cifmw_cephadm_prometheus_container_ns: "quay.io/prometheus"
+cifmw_cephadm_alertmanager_container_image: "{{ cifmw_cephadm_prometheus_container_ns }}/alertmanager:v0.25.0"
+cifmw_cephadm_grafana_container_image: "{{ cifmw_cephadm_container_ns }}/ceph-grafana:9.4.7"
+cifmw_cephadm_node_exporter_container_image: "{{ cifmw_cephadm_prometheus_container_ns }}/node-exporter:v1.5.0"
+cifmw_cephadm_prometheus_container_image: "{{ cifmw_cephadm_prometheus_container_ns }}/prometheus:v2.43.0"