COIL: Migrate to HEAD

Update links to point to HEAD

BUG=b:224796805
TEST=navigate to updated link and/or N/A

Change-Id: I8793365850577b8eb773b7ede156deac056759b5
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/tauto/+/5159947
Commit-Queue: Derek Beckett <dbeckett@chromium.org>
Auto-Submit: Jonathon Murphy <jpmurphy@google.com>
Commit-Queue: Jonathon Murphy <jpmurphy@google.com>
Tested-by: Jonathon Murphy <jpmurphy@google.com>
Reviewed-by: Otabek Kasimov <otabek@google.com>
Reviewed-by: Derek Beckett <dbeckett@chromium.org>