Avoid crash for stss sync sample number 0 am: 5c364997a3 am: e77a32bd3d am: ab28d49e41  -s ours am: 73db408aa3 am: 0bb0a8e1e8 am: 4d86bef7f7 am: 241f5feb8a am: a7cec6180f am: d022170614 am: cbdc2b7899 am: c9f14c3442
am: 08bb4c4a5b

Change-Id: If0971ae6886ac4ba33eb4c77dcb8f4f72f64d775