Add offload subdir to test_runner.Config.Harness

Thus moving it out of a constant in the recipe file

BUG: 1022986
Change-Id: I1b7e197576c2720c580fe42c1eb38b84c1e9235b
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/infra/proto/+/2128805
Tested-by: Jacob Kopczynski <jkop@chromium.org>
Auto-Submit: Jacob Kopczynski <jkop@chromium.org>
Reviewed-by: Alex Zamorzaev <zamorzaev@chromium.org>
Commit-Queue: Alex Zamorzaev <zamorzaev@chromium.org>
2 files changed