FILE PHOTO: Newly appointed Britain's Chancellor of the Exchequer Rishi Sunak leaves Downing Street in London, Britain February 13, 2020. REUTERS/Toby Melville/File Photo LONDON (Reuters) - Britain is expected to double spending on flood defenses to 5.2 billion pounds ($6.78 billion) when finance minister Rishi Sunak delivers his budget, the Treasury said on Saturday, following