logging - fix defaults in the image to just use stdout - no disk

the default logging in the image will use disk if persistence is enabled. this can consume the entire disk. By default we should just redirect to the console and let normal console scraping deal with persistence.

If the defaults are better, the need for customisation diminishes. 

The image does not need to allow any configuration options, or a very minimal set configurable at a very high level.

if defaults don't work, provide a custom full config via env vars and configMap