[Helix] Go back to 1604 for now (#22514)
[Helix] Go back to 1604 for now (#22514)

1804 doesn't have enough cores to support our volume right now
aspnet/AspNetCore,aspnet/AspNetCore,aspnet/AspNetCore,aspnet/AspNetCore,aspnet/AspNetCore,aspnet/AspNetCore,aspnet/AspNetCore,aspnet/AspNetCore,aspnet/AspNetCore