Looks like an issue with the logic that handles whether the PVC is created or not (https://github.com/ansibleplaybookbundle/postgresql-apb/blob/master/tasks/main.yml#L41), similar for each postgresql|mariadb|mysql.
https://github.com/ansibleplaybookbundle/postgresql-apb/pull/57 https://github.com/ansibleplaybookbundle/mysql-apb/pull/41 https://github.com/ansibleplaybookbundle/mariadb-apb/pull/39
Verified and Passed with images in comment 3
Since the problem described in this bug report should be resolved in a recent advisory, it has been closed with a resolution of ERRATA. For information on the advisory, and where to find the updated files, follow the link below. If the solution does not work for you, open a new bug report. https://access.redhat.com/errata/RHBA-2018:2652