Proposal: Add ReadOnlyFs option to default execution parameters config

[PSanetra]

It would be nice to extend the default execution parameters config with a ReadOnlyFs field. Currently it is only possible to declare that option explicitly on container start (e.g. with docker run --read-only). It would be better if the image author could declare this option already during the image build as the author has more knowledge about the fact if the container needs a writable filesystem at runtime or not.

Another problem with declaring the read-only option separately from the image (e.g. in a Helm chart for Kubernetes deployment) is that the requirement for a writable filesystem may change with a new image release.