TestWorkflowService doesn't pass headers into workflow retry

## Expected Behavior
The subsequent workflow runs after a failure of the first run should get the same set of headers as input.

## Actual Behavior
When we use TestWorkflowService, workflow retry runs get an empty set of headers.

## Specifications

  - Master: b682a2d68c5d4caae1585d34bae5d8d8e92253bd
