Skip Uprev/BuildImage stage properly with "Not running" message logged

BUG=chromium:375492
TEST=`buildbot/run_tests` passes

Change-Id: Ibc1f3b72562892f1422481d6a6d665de3fbb2064
Reviewed-on: https://chromium-review.googlesource.com/200662
Reviewed-by: David James <davidjames@chromium.org>
Commit-Queue: Yu-Ju Hong <yjhong@chromium.org>
Tested-by: Yu-Ju Hong <yjhong@chromium.org>
1 file changed