[automerger] Return error for invalid reorder parameter am: 4286d31e9e am: df2bef9a86 am: e7950035a8 am: b596887685 am: 3d1c41dfb1 am: a5af46e7c4 am: a01ece8616 am: a4843b0735 am: 884157609f

Change-Id: I1578a37ea0fb33c258cd08550fc31c849fb1eaa4