The savepoint backend configuration allows both jobmanager and filesystem as values. The jobmanager variant is used as default if nothing is configured.
As part of FLIP-10, we want to get rid of this distinction and make all savepoints go to a file. Savepoints backed by JobManagers are only relevant for testing. Users could only recover from them if they did not shut down the current cluster.
Deprecate the savepoints.state.backend.fs.dir and add state.savepoints.dir as new config key. This is used as the default savepoint directory. Users can overwrite this.