Don't require an access token in log4j appender when configuration class is provided

[diegov]

Description of the change

The configuration class can provide the access token, so we don't need it to be required as an appender parameter when a configuration class is configured.

This change will validate that either a configuration class or an access token is provided (both are also allowed), and will fail to initialise the appender only when neither is present.

Type of change

• [x] Bug fix (non-breaking change that fixes an issue)
• [ ] New feature (non-breaking change that adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)

Related issues

None

Checklists

Development

• [x] Lint rules pass locally
• [x] The code changed/added as part of this pull request has been covered with tests
• [x] All tests related to the changed code pass in development

Code review

• [ ] This pull request has a descriptive title and information useful to a reviewer. There may be a screenshot or screencast attached
• [x] "Ready for review" label attached to the PR and reviewers mentioned in a comment
• [ ] Changes have been reviewed by at least one other engineer
• [ ] Issue from task tracker has a link to this pull request

[shortcut-integration[bot]]

This pull request has been linked to Clubhouse Story #79314: Rollbar Java Log4j2 integration requires an accessToken even when using configProviderClassNam.