Add OIDC compatibility

OIDC authentication requires a different Docker image from the one used for publishing repository content. This customized image loads the OIDC module to enable the connection and loads other modules listed in the Helm Chart values file by default.

Forcing the container to load the default Helm Chart value modules results in the error "module is built-in and can't be loaded," causing the container to stop.

This Helm Chart must be compatible with different Apache2 images. Therefore, a new conditional is added to avoid loading the default modules if CUSTOM_MODULES is defined.

Phabricator task: T10135

Signed-off-by: Pablo Vigo pvigo@collabora.com