[buildbucket] Serve half of dev ScheduleBuild requests
[buildbucket] Serve half of dev ScheduleBuild requests

Bug: 1042991
Change-Id: Ief84fb59f98d361aba9e215cfd9f2c197306c5df
Reviewed-on: https://chromium-review.googlesource.com/c/infra/luci/luci-go/+/2853743
Reviewed-by: Nodir Turakulov <ef4933a197ef7b4b3f55f1bec4942aead3637a2a@chromium.org>
Commit-Queue: smut <95deb7aa15d4c615299e47e7688551456568b1fb@google.com>

luci/luci-go,luci/luci-go,luci/luci-go,luci/luci-go,luci/luci-go,luci/luci-go