SCT RDO updates to reduce size for overlay MC (ATLASSIM-3903)
See merge request !20374 (merged)
Although physics results will not be changed, containers in RDO will be changed. (ESD and AOD will not be changed.)
!20213 (merged) (merged) is the corresponding MR for the master branch.
!20374 (merged) (merged) is the corresponding MR for the 21.3 branch.
Now this MR is to have the forward compatibility in 21.0 to RDO files produced with master or 21.3, and not to reduce the RDO file size because the old
SCT_RawDataContainer_p3 is used for persistification.