After spending a week in London, I noticed that the richest gals replaced their sneakers with this elegant shoe style, and Scarlett Johansson is one of them. A few days ago, Johansson donned the flats that are everywhere from Kensington to Chelsea, and her luxe look is under $35! The Paper Tiger actress was seen strolling around downtown London while wearing a gingham-print maxi dress, crossbody bag and burgundy Mary Jane flats. Her shoe choice …