Add has_custom_requirement field to Attempt proto
Add has_custom_requirement field to Attempt proto

Bug: 1069250
Change-Id: I0e60a49e14592f6ca057d53a8b9a22d92dcabeaa
Reviewed-on: https://chromium-review.googlesource.com/c/infra/luci/luci-go/+/2145792
Commit-Queue: Quinten Yearsley <747cf52e0cef2e3e9371802a2d344b6c87126a4b@chromium.org>
Reviewed-by: Andrii Shyshkalov <a30c74fa30536fe7ea81ed6dec202e35e149e1fd@google.com>

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