Already seen at 200 venues across North America, "Bear Grease," the all Indigenous musical, arrives in New York for a three-month residency. While its subtitle declares that it is a "reimagining of the musical Grease by Jim Jacobs and Warren Carey told through an Indigenous lens," it is more of a variety show with songs, dances, and video while  including iconc scenes and songs from "Grease" paying tribute to Nati…