Merge from master branch of Widevine repo of http://go/wvgerrit/66065
Merge from oemcrypto-v15 branch of Widevine repo of http://go/wvgerrit/63080
This is for the reference code, the unit tests, and the oemcrypto adapter.
Bug: 116414218
Test: unit tests
Test: tested as part of http://go/ag/5501993
Change-Id: I05a631f6cfcf1584a748b3a0c9ae48633893589f