Fix error with command ansible module and pipes

From the ansible command module[1]:
The command(s) will not be processed through the shell, so variables like $HOME and
operations like "<", ">", "|", ";" and "&" will not work.
Use the shell module if you need these features.

[1] https://docs.ansible.com/ansible/latest/modules/command_module.html

Change-Id: I87d1e9621a5eccf3c90ae9b8ac683bc83006b0b7
Closes-Bug: 1864855

tripleo_ansible/roles/backup_and_restore/backup/tasks/db_backup.yml

@@ -48,7 +48,8 @@
     - bar_create_recover_image
 
 - name: Get the mysql container id when galera is enabled
-  command: |
+  shell: |
+    set -o pipefail
     {{ tripleo_container_cli }} ps -a | grep galera | awk '{print $1}'
   when: enabled_galera
   register: galera_container_id