Fix PRDtoTrackMap config for SiSPSeededTracksFinalCfg (ATLIDTRKCP-593)
f"InDet/ITkPRDtoTrackMap{extension}" is only defined for secondary tracking passes. For the main tracking pass, the collection PRDtoTrackMapMerge_CombinedInDet/ITkTracks should be used instead.
In the config used to produce TrackParticles from SiSPSeededTracks, it was wrongly assumed that the primary pass could be identified by an empty extension, but this is only the case for default pp configuration. ATLIDTRKCP-593 highlighted this was not appropriate for the HeavyIon config. The config is updated here to check whether the extension is actually the one from the primary pass, even if it's not the default config.