'Dough' - in the slang sense of money - started life as an americanism in the middle of the 19th century. The idea of 'rolling' in it simply suggests that there is a large enough amount of it in oder to enable you to do that!
It's a nice idea that dough = money is a bit of Cockney rhyming slang. Sadly, the earliest recorded use of the word in this way appeared in a Yale University magazine published in 1851.
As a result, the scholars at The Oxford English Dictionary have this to say as the third definition of 'dough'...(quote) "Money. slang (orig US)."
Bread = money is also an americanism, having started life among jazzmen in the 1930s. So, neither 'dough' nor 'bread' = money originated as Cockney rhyming slang.