Enable measurement of trigger EDM in AthenaMT
Enabling size measurement required a couple of fixes.
Tested with test_trigAna_q221_RDOtoAOD_mt1_build.sh, which uses the LS2_v1 menu.
Checked that the functionality of Run-2 trigger EDM size measurement (v7 menu) is not affected.
After this MR is merged, ART trigger MT tests will produce the file AOD.pool.root.checkFiletrigSize.txt needed by trigger EDM size monitoring web page - tagging @mamuzic.
Edited by Oleg Kuprash