Sync reference files in MuonGeoModelTestR4 and ActsEventCnv

In !71240 (merged), @jojungge pointed out that we need to keep the MuonGeoModelTestR4 and ActsEventCnv reference files in sync. This is an attempt to do this.

This might be easier to review once !72140 is accepted, since all commits other than the last one are actually from that MR; I cannot rebase / cherry-pick because that MR introduces a file modified by this MR.