DCOM-290: [GH-374] getManagerForClass should try to retrieve the default manager

[doctrinebot]

Jira issue originally created by user @doctrinebot:

This issue is created automatically through a Github pull request on behalf of elernonelma:

Url: https://github.com/doctrine/common/pull/374

Message:

getManagerForClass should try to retrieve the default manager instead of the first one found in the list.