Support collecting attr keyval in generate_test_report and local_dash

FAFT now records the firmware version info to the attr keyval. This CL makes
generate_test_report support getting this attr keyval info, such that
local_dash can get this version info even if the sysinfo is not available.

BUG=chromium-os:36326
TEST=generate_test_report --csv --attr --sort-chron /tmp/run_remote_tests.Czsx
/tmp/run_remote_tests.Czsx/firmware_DevMode/firmware_DevMode.normal,PASS,fw_version=link_v1.2.111-d07166a,fwid=Google_Link.2695.1.128,hwid=X86 LINK TEST 6638
/tmp/run_remote_tests.Czsx/firmware_DevMode,PASS
TEST=local_dash to generate the json file even if sysinfo is not available

Change-Id: Ie7cd9c99c10d82fc48cd13518e5ebc43fd66a9ea
Reviewed-on: https://gerrit.chromium.org/gerrit/38900
Reviewed-by: Mike Truty <truty@chromium.org>
Commit-Ready: Tom Wai-Hong Tam <waihong@chromium.org>
Tested-by: Tom Wai-Hong Tam <waihong@chromium.org>
2 files changed