lakitu: Update guest-agent to v20210408.00

BUG=b/184870114
TEST=presbumit
RELEASE_NOTE=Update guest-agent to v20210408.00

Change-Id: I6aecff6c4fbd46a2cc92b91922e8ee6294a931ec
Reviewed-on: https://cos-review.googlesource.com/c/cos/overlays/board-overlays/+/15494
Tested-by: Cusky Presubmit Bot <presubmit@cos-infra-prod.iam.gserviceaccount.com>
Reviewed-by: Dexter Rivera <riverade@google.com>
4 files changed