test_platform: fix the type of parent build id for TestCaseResult

As we use test runner's build ID to identify a test run, all fields
representing it should be build ID type(int64).

BUG=chromium:1085958
TEST=./generate.sh

Change-Id: I5efcfec94aa15b2c855f62932ee8b7b339f67f54
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/infra/proto/+/2281286
Reviewed-by: Alex Zamorzaev <zamorzaev@chromium.org>
Commit-Queue: Xinan Lin <linxinan@chromium.org>
Tested-by: Xinan Lin <linxinan@chromium.org>
2 files changed