Mark x86-alex as the release master.

x86-alex is the release master on the waterfall so it needs to be marked
as such in the config.

BUG=none
TEST=unit test

Change-Id: Ibd9a44e9267a03e9d02369170e7d03d913dc71b2
Reviewed-on: https://chromium-review.googlesource.com/199623
Reviewed-by: Dharani Govindan <dharani@chromium.org>
Tested-by: Dharani Govindan <dharani@chromium.org>
1 file changed