MongoDB persistency on commit should happen before other afterCompletion

Today MongoDB commit is called in a transaction synchronization when a session is used
in RepositoryService$SessionSynchronization.afterCompletion.
The order of beforeCompletion and afterCompletion hooks are given by the order of registration to the transaction.
This means that custom synchronization might be called before data are persisted in MongoDB resulting in visibility problem on afterCompletion hook.

The mongo persistence should be the first hook to be executed, this is possible using geronimo registerInterposedSynchronization