New tuning of TRT validity gate for run2 and 3

This is a resubmit of an earlier request that had grown too old. To suppress out-of-time pile-up, TRT RIOs are required to pass the low level threshold within a certain time window, the validity gate (VG). This MR implements a new tuning of the VG using a sample of 2018 data, separately for Xe and Ar hits. As a result, you save about 1% of the RDO space (for Argon hits) with no loss of efficiencies. However, there are slight changes in q431 output, so the request also contains a reference file update.