Add mapping for mariadb rdo package

Mariadb package in RDO repository is mariadb-galera-server, but
this name is mapped to MariaDB-Galera-server because of
mariadb installed from mariadb.org.

To avoid mapping conflicts mariadb-rdo uses virtual package name
mariadb-rdo-galera-server which is mapped to mariadb-galera-server.

Change-Id: Idf77d91876baeb81d89eb688808b892ece2bf19a
Merge "Add mapping for mariadb rdo package"