By Uditha Jayasinghe COLOMBO (Reuters) -Sri Lanka will shut schools and only allow fuel supplies to services deemed essential like health, trains and buses for two weeks starting Tuesday, a minister said, in a desperate attempt to deal with a severe shortage. Sri Lanka is suffering its worst economic crisis, with foreign exchange reserves at a record low and the island of 22 million struggling to pay for essential imports of food, medicine and, most critically, fuel. Industries like garments, a big dollar earner in the Indian Ocean nation, are left with fuel for only about a week to 10 days. C…