This pull request adds a full cluster restart test for a Rollup job.
The test creates and starts a Rollup job on the cluster and checks
that the job already exists and is correctly started on the upgraded
cluster.
This test allows to test that the persistent task state is correctly
parsed from the cluster state after the upgrade, as the status field
has been renamed to state in #31031.
The test undercovers a ClassCastException that can be thrown in
the RollupIndexer when the timestamp as a very low value that fits
into an integer. When it's the case, the value is parsed back as an
Integer instead of Long object and (long) position.get(rollupFieldName)
fails.
be9292cac6