[automerger] M3UParser: detect variant streams without EXT-X-STREAM-INF am: f3e0afb82f am: 4b29913d94 am: a6bd71fcb8 am: 1816776c89 am: 86eb461699 am: e31e750544 am: 67835c7025 am: 9f344e0b9c am: 6e2df031fa am: 8d6c333529

Change-Id: I992da5131a99270d4bf008318d10ce6c2e6a64ca