Descriptor class that should be used to help set up an AFH host channel classification for the controller.

The bits in each byte of this descriptor are used to tell the controller which channels the host anticipates will become busy and so advisable for Bluetooth to avoid. Such channels are referred to as 'bad', and are represented by bits set to 0. Channels that are not 'bad' are referred to as 'unknown' implying simply that the host has no knowledge that they are, or are about to become 'bad'. These are represented by bits set to 1. Note: The Bluetooth specification demands that at least 20 channels must be set to 'unknown'. Any attempt by the user of this class to set too many 'bad' channels will result in the return of a KErrNotSupported error, and the attempt having no effect.