Peter: Nope. It is a factory setting that cannot be changed.
Why would you want to change it?
By flashing 3 times, other drivers' are more likely to notice the signal and will know what your intentions are. If it only flashes once, it may look like you accidentally hit the signal stalk and/or not be noticed by other drivers.
Quite simply, Nope!
Why would you flash it once, that is not signalling anything.
Surely you have the owners manual for such a new car?