Implements the ability to split the screen by long-pressing a Taskbar icon. Bug: 217964720 Test: Manual Change-Id: I5d324d8ca912c10cc3c3de21cae98fad546b85ac
Bug: 216829535 Test: https://recall.googleplex.com/projects/f46cfe9c-8076-4efe-bf8a-b1cc4f1f5e1b/sessions/feb5db9c-9429-42c2-a124-777e66fd5f0b Change-Id: I34118975d0d7e15eb46b483f5a05447f5391e6fd
Bug: 216829535 Test: https://screenshot.googleplex.com/BNu6iWHGKV9sX7u Change-Id: Id7ef9093e24c0211cf9590b35399e1f4d5b55ecf