samples: Bluetooth: Update params in connected CS sample

This change is made to fix the currently broken CS samples, to prevent
them from just printing error messages like:
`Channel sounding not enough memory to store step data (530 > 512)`.

This change updates the CS config and procedure parameters. The
intention with the updated parameter selection is to use parameters that
result in:
- CS procedures with only a single CS subevent per procedure. This is
  required because the samples are not designed to support > 1 subevent
  per procedure and the samples will break down if > 1 subevent per
  procedure is generated.
- A limited number of CS steps per procedure. This is achieved by
  setting `.channel_map_repetition = 1` and only enabling a limited set
  of channels in the channel map. This is required because the samples
  are designed to transfer all of the step data from one procedure, from
  the reflector to the initiator, using a single GATT write operation
  which is limited to 512 bytes.

Signed-off-by: Erik Sandgren <erik.sandgren@nordicsemi.no>