Add Sandbox ID support

Merge from master branch of Widevine repo of http://go/wvgerrit/66078
Merge from oemcrypto-v15 branch of Widevine repo of http://go/wvgerrit/64022

This CL updates OEMCrypto ref code, unit tests, and core code for
setting the sandbox id before initializing OEMCrypto.

Test: unit tests only
Test: tested as part of http://go/ag/5501993
Bug: 115834255
Change-Id: Id9831680fe4db1c69413815931cae4bc80df0c01

libwvdrmengine/cdm/core/include/properties.h

@@ -64,6 +64,7 @@ class Properties {
                                      std::string* base_path);
   static bool GetFactoryKeyboxPath(std::string* keybox);
   static bool GetOEMCryptoPath(std::string* library_name);
+  static bool GetSandboxId(std::string *sandbox_id);
   static bool AlwaysUseKeySetIds();
   static bool UseProviderIdInProvisioningRequest();