Bug/gson removal

[payneBrandon]

PR Details

Description

After migrating away from Gson in the previous PR, it was noted that the Gson reference was still in the code base. This PR removes that and updates the one remaining file (OdeTravelerInformationMessage.java) which still had Gson references.

This PR also removes the single remaining usage of log4j. The ODE has previously migrated to use logback with a default static instance. There was one remaining class using the old log4j, as well as the pom.xml import. Both have been updated.

Related Issue

Motivation and Context

Code cleanup for more concise usage and more consistent development going forward.

How Has This Been Tested?

Tested locally.

Types of changes

• Defect fix (non-breaking change that fixes an issue)
• New feature (non-breaking change that adds functionality)
• Breaking change (fix or feature that cause existing functionality to change)

Checklist:

• I have added any new packages to the sonar-scanner.properties file
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
  ODE Contributing Guide
• I have added tests to cover my changes.
• All new and existing tests passed.

[TonyEnglish]

thx