Merge from Widevine repo of http://go/wvgerrit/125203
The OEMCrypto reference is not used/built on Android. It was being
published to aid OEMs in their development, but now the OPK library
is the implementation to be used by OEMs.
Bug: 187556088
Bug: 184866351
Test: Ran android/copy_files
Change-Id: Ie787bcf9c66a7605700c3dc29a8aa16406926ce3
42188c007a