This reverts commit c48318a3.

Reason for revert: likely broke ChromeOS

Original change's description:
> bot_update: Don't force solutions to be unmanaged.
> 
> gclient should be the one syncing the solutions to the appropriate
> revisions.
> 
> Bug: 850812, 853032
> Change-Id: Ieefc5661627d4864deb0d4e7053168a99da29d29
> Reviewed-on: https://chromium-review.googlesource.com/1102833
> Reviewed-by: Aaron Gable <agable@chromium.org>
> Commit-Queue: Edward Lesmes <ehmaldonado@chromium.org>

TBR=hinoka@chromium.org,agable@chromium.org,ehmaldonado@chromium.org

Change-Id: I7e110108a9687d703ea8be39cc83e0888f7813c6
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 850812, 853032, 855700
Reviewed-on: https://chromium-review.googlesource.com/1111925Reviewed-by: Andrii Shyshkalov <tandrii@chromium.org>
Commit-Queue: Andrii Shyshkalov <tandrii@chromium.org>