Set grafana-server user and password in ceph-dashboard role

This change adds two tasks to set grafana-api user and password
that are required to inject dashboard layouts to the external
grafana instance.
Without these two parameters the ceph-ansible playbook fails
showing an authorization error (HTTPError: 401 Client Error:
Unauthorized").

Closes: https://bugzilla.redhat.com/show_bug.cgi?id=1767365
Signed-off-by: fmount <fpantano@redhat.com>

roles/ceph-dashboard/tasks/configure_dashboard.yml

@@ -100,6 +100,18 @@
   run_once: true
   changed_when: false
 
+- name: set grafana api user
+  command: "{{ container_exec_cmd }} ceph --cluster {{ cluster }} dashboard set-grafana-api-username {{ grafana_admin_user }}"
+  delegate_to: "{{ groups[mon_group_name][0] }}"
+  run_once: true
+  changed_when: false
+
+- name: set grafana api password
+  command: "{{ container_exec_cmd }} ceph --cluster {{ cluster }} dashboard set-grafana-api-password {{ grafana_admin_password }}"
+  delegate_to: "{{ groups[mon_group_name][0] }}"
+  run_once: true
+  changed_when: false
+
 - name: set alertmanager host
   command: "{{ container_exec_cmd }} ceph --cluster {{ cluster }} dashboard set-alertmanager-api-host {{ dashboard_protocol }}://{{ grafana_server_addr }}:{{ alertmanager_port }}"
   delegate_to: "{{ groups[mon_group_name][0] }}"