Making RingerReFex to return dummy ringContainer
As reported in ATR-22704 there is a failure in ringerShapeHandle.isValid() check in TrigEgammaFastCaloHypoAlgMT.cxx which causes due to preprocessing failure in RingerReFex (not giving back a ringerContainer). This MR will make sure RingerReFex will always create a dummy ringerContainer and when TrigEgammaFastCaloHypoAlgMT won't get a valid ringerContainer it will use this dummy Ringer Container. Adding @tamartin , @fernando , @cjmeyer , @mverissi