NIFI-13686 Make TestListFile.testFilterAge() more resilient

[jrsteinebrey]

to work with time delays that sometimes during execution

Summary

NIFI-13686

Tracking

Please complete the following tracking steps prior to pull request creation.

Issue Tracking

• Apache NiFi Jira issue created

Pull Request Tracking

• Pull Request title starts with Apache NiFi Jira issue number, such as NIFI-13686
• Pull Request commit message starts with Apache NiFi Jira issue number, as such NIFI-13686

Pull Request Formatting

• Pull Request based on current revision of the main branch
• Pull Request refers to a feature branch with one commit containing changes

Verification

1. I made sure the unit test worked for isMillisecondSupported true and false
2. I tested with artificial 5 second delay during the unit test and it still worked correctly.

Build

• Build completed using mvn clean install -P contrib-check
  • JDK 21

Licensing

No dependency changes

Documentation

No documentation changes

[gresockj]

Looks good, thanks for this fix, @jrsteinebrey !