update_payload: Implement checking for major version 2 payloads

This commit adds payload major version 2 support to paycheck.py --check.

For consistency, report messages for affected fields are kept the same across
both major version 1 and 2 checks, even if the particular field name does not
exist in one version.

BUG=b:794404
TEST=no errors during run_unittests and paycheck.py --check <major version 2
  payload> (./test_paycheck.sh does not pass for major version 2 payloads
  since applying is not implemented yet; no regressions when running on major
  version 1 payloads)

Change-Id: I3c5d0cbca3336c8136326ca52b19f659c7c741c9
Reviewed-on: https://chromium-review.googlesource.com/1105610
Commit-Ready: Tudor Brindus <tbrindus@chromium.org>
Tested-by: Tudor Brindus <tbrindus@chromium.org>
Reviewed-by: Amin Hassani <ahassani@chromium.org>

0 files changed, 0 insertions, 0 deletions