afdo_tools: add update_kernel_afdo script

This adds a script, update_kernel_afdo, which automatically updates
afdo_metadata/kernel_afdo.json. The changes are then shown with
git diff and can be committed with git commit after review.

BUG=None
TEST=Ran the script, including with some variations to see the failure modes.

Change-Id: Ibe473a80a874e32ddcb9c292e1c018fac72e7292
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/toolchain-utils/+/2261732
Commit-Queue: Bob Haarman <inglorion@chromium.org>
Tested-by: Bob Haarman <inglorion@chromium.org>
Reviewed-by: Tiancong Wang <tcwang@google.com>
1 file changed