Only specify values that override default in Marketplace Deployer

The following discussion from https://gitlab.com/charts/deploy-image-helm-base/merge_requests/48 should be addressed:

• @WarheadsSE started a discussion:

  We should not need anything here that is not overridden. The sub-charts global definition should end up merged with this.

  I emphasize "should", because, you know, Helm.