I have noticed it many times in the region where I live. I don't know if its common World wide. But I think someone else would have noticed it. So why does this happen ?
In general, babies do not naturally urinate when hearing that sound.
However, there is a technique of instilling a Pavlovian response in your baby to urinate when hearing that sound. You start by holding the baby diaper-free, and making the sound when they urinate, so that they make that association between the sound and the sensation of urination. After lots of reinforcement, you can get the baby to urinate when it hears the sound, so babies are potty-trained earlier than they otherwise would be.
It's part of a process called "elimination communication"
It's less common in Western countries, probably because most people prefer to, and have the means to either buy lots of disposable diapers, or have the means to easily wash their cloth ones over and over again.