Bluetooth: Audio: Shell: Runtime config of CAP/GMAP ACs

Modifies the audio configuration (ac) commands for CAP
and GMAP to use the default presets instead of supplying
the preset as arguments. This will allow the user to
use the `bap preset` command to configure everything in the
codec configuration before the AC commands are issued.

Signed-off-by: Emil Gydesen <emil.gydesen@nordicsemi.no>