Classic confinement for existing Helm snap

The kubectl snap is intended to move to strict confinement soonish (cc @Wimpress), AIUI. Is this snap only meant to be used with the kubectl snap? If so, I would suggest that kubectl be adjusted to put its configuration somewhere else, or, we add a kubernetes-observe interface to allow accessing the configuration.

Nevertheless, the requirements for this request for classic are understood. @evan, @Wimpress, @popey - can one of you perform the other parts of Process for reviewing classic confinement snaps?