[Misc] Apply SonarCloud rule cpp:S3230
SonarCloud rule fix
- Rule name: Do not use the constructor's initializer list for data member "m_schema". Use the in-class initializer instead.
- Rule code: cpp:S3230
- Rule link: https://sonarcloud.io/project/issues?open=AYjy0_uAx-2o8nUjJbcD&id=cern-cta_CTA