infra: Undo migration of linux-gcc-rel (Week 3a)

This builder is failing due to missing compiler. The solution will
probably be to use ATS, but let's revert this change first.

To bypass the CQ/tree which is closed:
NOTRY=true
NOTREECHECKS=true
NOPRESUBMIT=true

Bug: 950413
Change-Id: I9a527604d1f03102b6c25e9bbe9b1bb60d03e46c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1656729
Reviewed-by: Eric Foo <efoo@chromium.org>
Commit-Queue: Simon Que <sque@chromium.org>
Cr-Commit-Position: refs/heads/master@{#668611}
1 file changed