Add Entitlement License to OEMCrypto

This CL adds entitlement license features and moves cipher mode from
LoadKeys to SelectKeys.

Merge from Widevine repo of http://go/wvgerrit/41660

bug: 70334840 Entitlement License - cdm layer
bug: 70334345 Entitlement License - reference code and unit tests

test: Entitlement license unit tests pass.
Change-Id: Ic7d7f42c15e6d83ef7fcfd8a866c778adc4c8095

libwvdrmengine/cdm/core/include/crypto_session.h

@@ -43,7 +43,8 @@ class KeySession {
                                    const std::string& provider_session_token,
                                    CdmCipherMode* cipher_mode,
                                    const std::string& srm_requirement) = 0;
-  virtual OEMCryptoResult SelectKey(const std::string& key_id) = 0;
+  virtual OEMCryptoResult SelectKey(const std::string& key_id,
+                                    CdmCipherMode cipher_mode) = 0;
   virtual OEMCryptoResult Decrypt(
       const CdmDecryptionParameters& params,
       OEMCrypto_DestBufferDesc& buffer_descriptor,
@@ -241,7 +242,8 @@ class CryptoSession {
       const std::string& private_key, const std::string& iv,
       const std::string& wrapping_key, std::string* wrapped_private_key);
 
-  CdmResponseType SelectKey(const std::string& key_id);
+  CdmResponseType SelectKey(const std::string& key_id,
+                            CdmCipherMode cipher_mode);
 
   static const OEMCrypto_Algorithm kInvalidAlgorithm =
       static_cast<OEMCrypto_Algorithm>(-1);