Jem Aswad Senior Music EditorA long-running battle between the estate of the late R&B singer Aaliyah Haughton and her uncle/ former manager/ label chief Barry Hankerson broke into the open on Wednesday after teasers about forthcoming music were posted online.The singer, who died in a plane crash at the age of 21, is arguably the most popular and prominent artist whose top album is not available on streaming services, due to a conflict between Hankerson and the estate that has gone on for the