signer: Reland "Check the list of android image files"

Previous change I5e8b4d848f30f53fae58c721c9b7ddcfbfea9852
was reverted because the check did not pass if the
signing process adds new files to the image.

The new check alerts only when we miss files in the original image.

BUG=b:230434967
BRANCH=None
TEST=Run ./sign_official_build.sh locally

Signed-off-by: Daichi Hirono <hirono@chromium.org>

Change-Id: If8e9eeb9568fefcde92d737b356fa84b865b05c9
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/vboot_reference/+/3653721
Commit-Queue: Shao-Chuan Lee <shaochuan@chromium.org>
Tested-by: Daichi Hirono <hirono@chromium.org>
Commit-Queue: Daichi Hirono <hirono@chromium.org>
Auto-Submit: Daichi Hirono <hirono@chromium.org>
Reviewed-by: Shao-Chuan Lee <shaochuan@chromium.org>
1 file changed