AthenaPoolCnvSvc: Update PoolWriteConfig.py to reflect the latest ROOT configuration optimizations
This MR migrates the POOL/ROOT file setting optimizations to the new-style configuration. Overall in the context of ATLASSIM-4274 and ATEAM-660.
This MR migrates the POOL/ROOT file setting optimizations to the new-style configuration. Overall in the context of ATLASSIM-4274 and ATEAM-660.