Format of the channel availability. Can be ALL_CHANNELS (the rest of the fields will not be set), CHANNEL_TYPE (only advertising_channel_type type will be set, the category is available to all sub types under it) or CHANNEL_TYPE_AND_SUBTYPES (advertising_channel_type, advertising_channel_sub_type, and include_default_channel_sub_type will all be set).
Channel subtypes under the channel type the category is available to.
Whether default channel sub type is included. For example, advertising_channel_type being DISPLAY and include_default_channel_sub_type being false means that the default display campaign where channel sub type is not set is not included in this availability configuration.