Update tests using mongodb.image to be able to consume arm64v8/mongo

[mjurc]

Our nosql coverage uses bitnami/mongodb, which doesn't release multiarch container right now. This is problematic for testing nosql capabilities on OCP on ARM.

arm64v8/mongo provides the container to run MongoDB on ARM, but the container is based on library/mongo rather than on bitnami container we use. Replacing the currently used container with the arm64v8/mongo results in DB never reaching readiness.

We should either replace our default mongodb container by the library/mongo or create some sort of glue that would enable us to use both. I'd be inclined to use the official image.