Yes, it's British. 'Trolley' is the British equivalent of 'shopping cart' in US English - in other words, the metal basket on wheels which customers push around supermarkets. 'Trolley rage' describes customers' unreasonably aggressive behaviour towards other shoppers. For example, a customer might violently push another person out of the way in order to get to the last bargain on the shelves, grab items out of another shopper's trolley, or even attack them in order to get hold of the desired merchandise. The American equivalent, as you might expect, seems to be 'Shopping Cart Rage.' These expressions are based on the more common phrase 'road rage' to describe the sudden madness and violent behaviour towards other drivers on the road.

As far as I know, we don't have this term in the US. I had never heard it before today. Here's the definition I found: https://www.englishforums.com/English/TrolleyRage/bzlvpd/post.htm In my part of the US those trolleys are called baggage carts or luggage carts.