Use gitiles_commit in go binaries rather than manifest commit.

Currently all go binaries assume we are reading from the private
manifest. Update to use gitiles_commit so it can determine whether to
get the private or public manifest.

BUG=chromium:1009192
TEST=./run_tests and local runs

Change-Id: Ib1c7803780c9741de3d1037f25fabfaf3457ea44
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/infra/go/+/2332756
Reviewed-by: Sean Abraham <seanabraham@chromium.org>
Reviewed-by: David Burger <dburger@chromium.org>
Commit-Queue: Navil Perez <navil@google.com>
Tested-by: Navil Perez <navil@google.com>
7 files changed