[automerger] Add some error/overflow checks in codebook handling am: 6eb63e1192 am: bc4bde3bee am: 632704bab3 am: 9cea7b942e am: 57035e3928 am: 6d0e814689 am: 14cbdba347
am: c113668f32

Change-Id: I837b06b16ecd03a237cf0eefb9c63ca442cbce25