[automerger] Fix DynamicRefTable::load security bug am: 8cf0f988b0 am: d65dbf91ce am: aeb2fc64d9 am: 0938689606 am: 6f76fbfc69 am: 69b14d2a1a am: c7e3991628 am: c3aa2a4d3f am: 648a950ce9

Change-Id: I313ac2c564ba5c8f094a37160d9ac5198f1d5aea