Increment to version R155-16812.0.0

Generated by release-main-orchestrator.

Cr-Build-Url: https://cr-buildbucket.appspot.com/build/8671447760829352881
Cr-Automation-Id: cros_version/bump_version
Change-Id: If589af0ab8605639a659244ebb643b88d41f65ed
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/overlays/chromiumos-overlay/+/8360255
Bot-Commit: chromeos-ci-release@chromeos-release-bot.iam.gserviceaccount.com <chromeos-ci-release@chromeos-release-bot.iam.gserviceaccount.com>
Tested-by: chromeos-ci-release@chromeos-release-bot.iam.gserviceaccount.com <chromeos-ci-release@chromeos-release-bot.iam.gserviceaccount.com>