Install MariaDB-shared
Install MariaDB-shared

The MariaDB-shared package has special metadata that states that it
replaces the existing mariadb-libs that comes from CentOS or RDO.
yum will happily trample the existing packages and install the
MariaDB upstream packages, but dnf is more strict when it comes to
obsoleting packages.

Long story short: yum has let us do some bad things.

This patch ensures we install MariaDB-shared explicitly as part of
the package installation on CentOS.

Implements: blueprint centos-and-dnf
Change-Id: Ib67f7e4e40c0a1d6568c231c2ae50abcd0553992

openstack/openstack-ansible-galera_client,openstack/openstack-ansible-galera_client