Makes the Random Engine of AthRNGSvc configurable via SimFlag.
Gives an option to set the random engine to MixMax via simFlags:
simFlags.RandomSvcMT.set_Value_and_Lock('AthMixMaxRNGSvc')
Gives an option to set the random engine to MixMax via simFlags:
simFlags.RandomSvcMT.set_Value_and_Lock('AthMixMaxRNGSvc')