WIP: Track particle cov matrix 21.2 20190611
requested to merge tstreble/athena:TrackParticleCovMatrix-21.2-20190611 into TrackParticleCovMatrix-21.2-20190611
Implemented changes discussed in #24240
Tested to run fine in RAW to AOD
Currently checking ESD to AOD step started from an ESD generated with old schema
Edited by Thomas Strebler