TrackState Covariance matrix needs different conversion

[andresailer]

k4LCIOReader/k4LCIOReader/src/k4LCIOConverter.cc

Line 358 in d92c743

_covMatrix[i] = rCM[i];

The LCIO covariance matrix is lower triangle, while the one in EDM4hep is the upper triangle.

http://lcio.desy.de/v02-09/doc/doxygen_api/html/classEVENT_1_1TrackState.html#a667b8774ce1b0f42dbae11a59dc7e09b

https://github.com/key4hep/EDM4hep/blob/e17d47ab9f17f3a56fb90550d307275cacd93153/edm4hep.yaml#L63

[andresailer]

Instead change to lower triangle in EDM4hep