[wpt] Fix wptrunner-ResultDB expected statuses

Fix-forward for a regression introduced in crrev.com/c/3868100. We
should report an expected status of `TIMEOUT`, not `ABORT`, as we had
done before that change.

Bug: 1299650
Change-Id: Ic2b11aa4f8aaffa9196de5b1cacbd20ef88e0fbb
Cq-Include-Trybots: luci.chromium.try:linux-wpt-identity-fyi-rel
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3869468
Auto-Submit: Jonathan Lee <jonathanjlee@google.com>
Commit-Queue: Weizhong Xia <weizhong@google.com>
Reviewed-by: Weizhong Xia <weizhong@google.com>
Cr-Commit-Position: refs/heads/main@{#1043038}