Revert "lakitu: Update guest-agent to v20210408.00"

This reverts commit 194da3e5d8548f7e41063249515854076955dc18.

Reason for revert: This broke validation tests by making b/176502144 occur very reliably

Change-Id: I32d7db721d058aee39940e62f00744e0e4bda222
Reviewed-on: https://cos-review.googlesource.com/c/cos/overlays/board-overlays/+/15830
Reviewed-by: Dexter Rivera <riverade@google.com>
Reviewed-by: Robert Kolchmeyer <rkolchmeyer@google.com>
Tested-by: Robert Kolchmeyer <rkolchmeyer@google.com>
4 files changed