v2.2/feature:playlist redundant cates and delay

tower: https://tower.im/projects/d4e0ff64158645f28d99a9ca72d0c27b/todos/b98995f9880244b6af6444d318ac1429
tower: https://tower.im/projects/d4e0ff64158645f28d99a9ca72d0c27b/todos/8a4973bc3ed04529857b481a1395a994

Change-Id: I596ebcc2b386a8e30d2d4329bfec94a36a003314