In order to ease logging of the various burn-in steps, this patch
proposes options to define the outpout files for all burn-in steps:
{'agent_burnin_cpu', 'agent_burnin_vm', 'agent_burnin_fio_network',
'agent_burnin_fio_disk'}_outputfile via a node's driver-info.
Story: #2007523
Task: #44102
Change-Id: I327cae5949d38e738d3c535487b3795d00ad8f1e