Revert "packages.proto: Add NeedsChromeSource endpoint."

This reverts commit 7e9f617ada9710f0f68a888023f7028c9913adfe.

Reason for revert: Breaks updating build API python bindings for chromite.  crbug/1086714 reopened with more detail.

Original change's description:
> packages.proto: Add NeedsChromeSource endpoint.
>
> BUG=chromium:1086714
> TEST=./generate.sh
>
> Change-Id: Icabbd23fa0ef51b49d5fb4ea668929a54d8221b9
> Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/infra/proto/+/2411808
> Reviewed-by: Michael Mortensen <mmortensen@google.com>
> Commit-Queue: Alex Klein <saklein@chromium.org>

Bug: chromium:1086714
Change-Id: Ie639d7e2b70210f188e0fe5991077c02c1a7ac71
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/infra/proto/+/2657035
Reviewed-by: LaMont Jones <lamontjones@chromium.org>
Commit-Queue: LaMont Jones <lamontjones@chromium.org>
2 files changed