Add decrypt hash support

[ Merge of http://go/wvgerrit/68083 ]

Add ability to query decrypt hash support, set a hash computed over a frame
and retrieve the last error at a later point.

Bug: 34080802
Test: WV unit/integration tests. New tests added to cdm_engine_test,
      libwvdrmdrmplugin_hidl_test and request_license_test.

Change-Id: I7548c8798c873a6af3e1cfc0df57c117e1e474a6

libwvdrmengine/cdm/core/include/cdm_session.h

@@ -193,6 +193,11 @@ class CdmSession {
                                         CdmSigningAlgorithm algorithm,
                                         const std::string& signature);
 
+  virtual CdmResponseType SetDecryptHash(uint32_t frame_number,
+                                               const std::string& hash);
+
+  virtual CdmResponseType GetDecryptHashError(std::string* hash_error_string);
+
   virtual metrics::SessionMetrics* GetMetrics() { return metrics_; }
 
  private: