[ Merge from http://go/wvgerrit/16499 ] Passing clear subsamples to OEMCrypto_CopyBuffer and encrypted subsamples to OEMCrypto_DecryptCTR was causing performance issues as a lack of crypto session information made it hard to associate clear and encrypted subsamples with each other. [ Based on a patch from Kelly Ren/Qualcomm ] b/26538744 Change-Id: I4644f197b2ec481f6aa89d3fce29b22ebb7b0c06