Merge from master branch of Widevine repo of http://go/wvgerrit/66072
Merge from oemcrypto-v15 branch of Widevine repo of http://go/wvgerrit/63764
This adds the function OEMCrypto_ResourceRatingTier to the oemcrypto referenece
code, dynamic adapter, and unit tests.
Bug: 117110800
Test: tested as part of http://go/ag/5501993
Change-Id: Idf47af405f0c69601108b75c788a97b30abdb39d