Add unit test for clear KCB in LS SDK 16.4 response

This is a merge from:
https://widevine-internal-review.googlesource.com/c/cdm/+/152897
and http://go/wvgerrit/153709

Adding a new OEMCrypto unit test will allow partners to correct a
problem earlier in their integration.

Verifies current oemcrypto implementation handles clear KCB in a
mocked 16.4 license response.

Unit test release date updated to 2022-06-17.

Test: run_x86_64_tests; opk_ta
Bug: 235870170
Bug: 234645065
Change-Id: I59fef2c25f5c007624447d4f46147d96adeddad9

libwvdrmengine/oemcrypto/test/oec_session_util.h

@@ -16,6 +16,7 @@
 #include <vector>
 
 #include "core_message_deserialize.h"
+#include "core_message_features.h"
 #include "core_message_serialize.h"
 #include "odk.h"
 #include "oec_device_features.h"
@@ -342,6 +343,18 @@ class LicenseRoundTrip
   // Fill the |core_response| substrings.
   virtual void FillCoreResponseSubstrings();
   void EncryptAndSignResponse() override;
+  // Encrypt and sign license response created from a specific odk version.
+  void EncryptAndSignResponseWithCoreMessageFeatures(
+      const oemcrypto_core_message::features::CoreMessageFeatures& features,
+      bool force_clear_kcb);
+  // Encrypt license response. This is used in EncryptAndSignResponse().
+  void EncryptResponse(bool force_clear_kcb = false);
+  // Create core license response with a specific ODK version. This is used in
+  // EncryptAndSignResponse().
+  void CreateCoreLicenseResponseWithFeatures(
+      const oemcrypto_core_message::features::CoreMessageFeatures& features);
+  // Sign license response. This is used in EncryptAndSignResponse().
+  void SignEncryptedResponse();
   OEMCryptoResult LoadResponse() override { return LoadResponse(session_); }
   OEMCryptoResult LoadResponse(Session* session) override;
   OEMCryptoResult LoadResponse(Session* session, bool verify_keys);