Update secondsTimeStep in selected unit tests

[JosueNina]

Description

Updated secondsTimeStep value in selected unit tests to address occasional test failures in GitHub CI

Related Issue

Closes #8492

Motivation and Context

Some unit tests intermittently fail in CI due to timing-related issues with secondsTimeStep.

Requires Documentation Change

No.

How Has This Been Tested?

The unit tests were executed locally to verify the changes, and the tests now pass consistently without failures.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• Refactor (non-breaking change which improves implementation)
• Performance (non-breaking change which improves performance. Please add associated performance test and results)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Non-functional change (xml comments/documentation/etc)

Checklist:

• My code follows the code style of this project.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.
• All new and existing tests passed.
• My branch follows the naming convention bug-<issue#>-<description> or feature-<issue#>-<description>

[Martin-Molinero]

Thanks!