Add buildtime package dependencies in cos-package-info.json.

This CL is adding the buildtime package dependencies (coming from
public overlays) into cos-package-info.json. This change is needed
for vulnerability tracker. drydock team will parses this file and
compare it against the vulnerability feed provided by COS. Based on
the intersection of the packages presentin the feed and
cos-package-info.json, the end customer will informed whether they
are running vulnerable COS version or not.

BUG=b/176256229
TEST=local build and remote build
RELEASE_NOTE=Add build time packages to cos-package-info.json.

Change-Id: I08651981c66a6ec351c0b70b1542e073b288290c
Reviewed-on: https://cos-review.googlesource.com/c/cos/overlays/board-overlays/+/10002
Reviewed-by: Vaibhav Rustagi <vaibhavrustagi@google.com>
Reviewed-by: Edward Jee <edjee@google.com>
Tested-by: Cusky Presubmit Bot <presubmit@cos-infra-prod.iam.gserviceaccount.com>
3 files changed