OEMCrypto Backwards Compatible Usage Table

Merge from widevine of http://go/wvgerrit/23283

This CL adds the backwards compatiblity functions to the new usage
tables in the oemcrypto mock reference code.

b/31458046
b/32554171

Change-Id: I04901d95aceb8910406f7c514c26c29c2c575322

libwvdrmengine/cdm/core/include/oemcrypto_adapter.h

@@ -48,7 +48,11 @@ OEMCryptoResult OEMCrypto_ShrinkUsageTableHeader(SecurityLevel level,
                                                  uint32_t new_table_size,
                                                  uint8_t* header_buffer,
                                                  size_t* header_buffer_length);
-
+OEMCryptoResult OEMCrypto_CreateOldUsageEntry(SecurityLevel level,
+    uint64_t time_since_license_received, uint64_t time_since_first_decrypt,
+    uint64_t time_since_last_decrypt, OEMCrypto_Usage_Entry_Status status,
+    uint8_t* server_mac_key, uint8_t* client_mac_key, const uint8_t* pst,
+    size_t pst_length);
 }  // namespace wvcdm
 
 #endif  // WVCDM_CORE_OEMCRYPTO_ADAPTER_H_