Revert MuonShowerInformationProducer back to legacy

MuonShowerInformationProducer was missed when we reverted all modules
using MuonDetLayerGeometry back to legacy to avoid thread safety
problems.
Merge pull request #3555 from Dr15Jones/revertMuonShowerInformationProducerBackToLegacy

Multithreading -- Revert MuonShowerInformationProducer back to legacy