Fix problem with gXENC quantities
This MR is meant to fix a bug reported in ATR-25669. A problem was observed for the values of gXENC inputs to L1Topo. This was caused by a wrong initialization of a vector of thresholds, which is now fixed. Since this issue was preventing us from switching on gXENC and gXERHO in the simulation, it is critical to get this merged before the P1 release is frozen.