This reverts commit 8274c197.

Reason for revert: b/170284879

Original change's description:
> Roll out new goma client binary VERSION=206
>
> Bug: b/167500848
> Change-Id: I6819bad98fd39787c91582dc0ed4ee3cf11dccc4
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/2449282
> Reviewed-by: Takuto Ikuta <tikuta@chromium.org>
> Reviewed-by: Fumitoshi Ukai <ukai@google.com>
> Reviewed-by: Junji Watanabe <jwata@google.com>
> Commit-Queue: Yoshisato Yanagisawa <yyanagisawa@chromium.org>

TBR=ukai@google.com,yyanagisawa@chromium.org,tikuta@chromium.org,jwata@google.com,yekuang@google.com,infra-scoped@luci-project-accounts.iam.gserviceaccount.com

Bug: b/167500848, b/170284879
Change-Id: Ia2cadff395be2570c4f5c7c0dd283979380038c5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/2455566Reviewed-by: Takuto Ikuta <tikuta@chromium.org>
Reviewed-by: Yoshisato Yanagisawa <yyanagisawa@google.com>
Commit-Queue: Takuto Ikuta <tikuta@chromium.org>
Commit-Queue: Yoshisato Yanagisawa <yyanagisawa@google.com>