The city’s top attorney on Friday dismissed concerns that Chicago could be liable for not informing residents that water meter installations at homes might have resulted in lead contamination.The Law Department’s posture is shaped by a victory earlier this year: A class-action lawsuit dismissed by a Cook County judge in April. That lawsuit is now pending before the 1st District Appellate Court.The plaintiffs in Berry v. City of Chicago, 16 CH 2292, alleged that city construction work on pipes and water mains …