SEOUL, April 27 (Reuters) - South Korea’s economy grew faster than expected in the first quarter, expanding 1.6% from the previous quarter, data from the Bank of Korea showed on Tuesday. That was faster than a revised 1.2% expansion in the final three months of 2020 and a median forecast for 1.0% growth in a Reuters poll. Gross domestic product expanded 1.8% year-on-year in the January-March period after shrinking a revised 1.2% three months earlier, also beating an expansion of 1.1% seen in the poll.