The root cause of the failure is the task timed out, which is acceptable as DetermineApproximatePassRatePipeline will retry the swarming task, which works if the first task succeeds but not if the first task fails due to an incorrect assert. This change is to allow for the conditions of the assert and fallback to a default timeout/iterations for the swarming task to be retried properly

The following revision refers to this bug:
  https://chromium.googlesource.com/infra/infra/+/2fee97afde0a5f7e79f788c76e0b84b8cd9b3f16

commit 2fee97afde0a5f7e79f788c76e0b84b8cd9b3f16
Author: Jeffrey Li <lijeffrey@chromium.org>
Date: Fri Aug 03 16:41:07 2018

[Findit] Flake Analyzer - Fixing assertion error for data points that encounter error early on

The assertion that fires is correct, however a corner case where the first task fails is not
accounted for. Rather than check for iterations and elapsed seconds, fallback to default
values immediately and allow DetermineApproximatePassRatePipeline to retry the swarming task.

Bug:  869697 
Change-Id: I6685f48afd0ffa90fbda0336c9be9321b86585a0
Reviewed-on: https://chromium-review.googlesource.com/1161507
Reviewed-by: Shuotao Gao <stgao@chromium.org>
Commit-Queue: Jeffrey Li <lijeffrey@chromium.org>

[modify] https://crrev.com/2fee97afde0a5f7e79f788c76e0b84b8cd9b3f16/appengine/findit/services/flake_failure/test/run_swarming_util_test.py
[modify] https://crrev.com/2fee97afde0a5f7e79f788c76e0b84b8cd9b3f16/appengine/findit/pipelines/flake_failure/determine_approximate_pass_rate_pipeline.py
[modify] https://crrev.com/2fee97afde0a5f7e79f788c76e0b84b8cd9b3f16/appengine/findit/services/flake_failure/run_swarming_util.py