Remove const to fix const-correctness issues of TrkAlignGenTools

Fix const-correctness issues of TrkAlignGenTools by removing const keyword.

http://atlas-computing.web.cern.ch/atlas-computing/links/distDirectory/gitwww/experimentalWebArea/nicos_web_areaconstmaster_Athena_x86_64centos7gcc8opt64BC7G8AthenaOpt/NICOS_Log_2019-06-08T1008/Tracking_TrkAlignment_TrkAlignGenTools.html

+ Tracking/TrkAlignment/TrkAlignGenTools
+ Tracking/TrkAlignment/TrkAlignInterfaces
+ InnerDetector/InDetAlignment/InDetAlignDBTools
+ InnerDetector/InDetAlignment/InDetAlignGeomTools
+ InnerDetector/InDetAlignment/InDetAlignNtupleTools
+ Tracking/TrkAlignment/TrkAlignGenAlgs
+ Tracking/TrkAlignment/TrkGlobalChi2AlignTools

were compiled by

cmake -DATLAS_PACKAGE_FILTER_FILE=../package_filters.txt  -DATLAS_ALLOW_TOOLHANDLE_NONCONSTNESS=OFF ../athena/Projects/WorkDir
make