This change also includes some code that was missing from
upgrade_checkout_commits.sh that actually generated the new
checkout_commits.env.
BUG=None
TEST=kokoro/kokoro_simulator.sh
docker/build_crosvm_base.sh
docker/build_crosvm.sh
Change-Id: If2505dd9af060d15c36eaf54741d4ae371f6a3c7
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/1641585
Reviewed-by: Daniel Verkamp <dverkamp@chromium.org>
Tested-by: kokoro <noreply+kokoro@google.com>
Tested-by: Zach Reizner <zachr@chromium.org>
Commit-Queue: Zach Reizner <zachr@chromium.org>