Which actively running Yelp business in "Gilbert" has got the most reviews? Give the business id.
actively running business refers to active = 'true'; 'Gilbert' is the name of city; most review refers to review_count = 'Uber'
SELECT DISTINCT T1.business_id FROM Business AS T1 INNER JOIN Reviews AS T2 ON T1.business_id = T2.business_id WHERE T1.active = 'true' AND T1.city = 'Gilbert' AND T1.review_count = 'Uber'