[automerger] M3UParser: detect variant streams without EXT-X-STREAM-INF am: f3e0afb82f am: 4b29913d94 am: a6bd71fcb8 am: 1816776c89 am: 86eb461699 am: e31e750544 am: 67835c7025

Change-Id: I354563d4b9687164e9860bdaa3d4fd94d2765934