DepositionGeant4: Do not Register RadioactiveDecay when using _HP Lists
The "_HP" Geant4 physics list already automatically registers the G4RadioactiveDecay
lists, hence adding it manually will lead to duplicate processes. This just checks for the presence of _HP
in the standard physics list name and then skips registering the decays.
(cc) Alina Landmann / TU Dortmund