wifidown: Use swarming.py in LUCI client

BUG=b:217935998
TEST=Ran the dashboard scripts with changes and made sure dashboard is populated

Change-Id: I508d59ff78fde86840211a810220fabd61f692e1
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crostestutils/+/3529828
Reviewed-by: Harpreet Grewal <harpreet@chromium.org>
Tested-by: Shijin Abraham <shijinabraham@google.com>
Commit-Queue: Shijin Abraham <shijinabraham@google.com>
4 files changed