Merge from widevine repo of http://go/wvgerrit/21560 For OEMCrypto v12 we explicitly require OEMCrypto_GetRandom to handle buffers up to 32 bytes long. This CL relaces the use of GetRandom with openssl's RAND_psuedo_bytes to fill test vectors. b/31464102 Change-Id: Ia0006b92bb12b98e9c130068dbb31b5f67281de2