Bluetooth: Audio: Fix issue with reset QoS on state change

The unicast client would simply reset all existing ISO QoS
when there was a state change to the QoS state (and only
update the stream QoS).

This caused issue with some ISO check later, as well
as wrongly resetting the data path too.

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