Created attachment 922435 [details]
[test run] After create a run, system save the new run's estimated_time as null.

Description of problem:
as summary.

Version-Release number of selected component (if applicable):
v3.8.10-1 on devel server.

How reproducible:
100%

Steps to Reproduce:
1.There are case1 with estimated_time '1d1h1m' and case2 with estimated_time '2d2h2m' in the same test plan.
2.Checked the two cases, the create a new run.
3.Inspect the default estimated_time for new run in create run page.
4.Save the new run, inspect estimated_time in the run detail page. 

Actual results:
In create new run page, system show estimated_time as '270180'.
In new run detail page, system show estimated_time as null, the value is 0 in table test_runs.

Expected results:
In create new run page, system show estimated_time as '3d3h3m'.
In new run detail page, system show estimated_time as '3d3h3m'.

Additional info: