fw_lab_triage_helper: DUT attribute discovery

Restores most DUT attribute functionality except for that which has
been sufficiently obviated by dashboarding.

TEST=ran utility (with the default of the faft-cr50 pool) and inspected
output
BUG=b:146062376

Change-Id: I8054ad6b60e4a2599d11bd7bbda37667292dde5c
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crostestutils/+/1961992
Tested-by: Kevin Shelton <kmshelton@chromium.org>
Commit-Queue: Kevin Shelton <kmshelton@chromium.org>
Reviewed-by: Greg Edelston <gredelston@google.com>
1 file changed