The per-channel visibility option of the assign-to-channel dialogs of Products and ProductVariants: keep the visibility they have in the active Channel (the default), or make them visible or hidden in the new Channels. Pass to the dialog's additional fields and to the mutation input.
channelAvailabilityFieldenabledInChannelenabledInChannel is undefined for the default, which leaves it out of the mutation input so
that the server copies the value from the active Channel; true for visible; and false for
hidden. channelAvailabilityField is null when there is only one Channel.
Example