When a galera cluster is stopped cleanly (i.e. it followed a sequential shutdown) , the last node to be stopped is marked as "safe to bootstrap", meaning this node should be the one to restart first the next time the cluster must be bootstrapped.

The mariadb operator should be able to benefit from that flag when bootstrapping a galera cluster. This can also improve situations where not all pods can be probed before deciding who should bootstrap the cluster, as the "safe_to_bootstrap" attribute is enough to decide.