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/oemcrypto/test/oec_device_features.cpp

@@ -29,6 +29,7 @@ void DeviceFeatures::Initialize(bool is_cast_receiver,
   supports_rsa_3072 = false;
   api_version = 0;
   derive_key_method = NO_METHOD;
+  OEMCrypto_SetSandbox(kTestSandbox, sizeof(kTestSandbox));
   if (OEMCrypto_SUCCESS != OEMCrypto_Initialize()) {
     printf("OEMCrypto_Initialize failed. All tests will fail.\n");
     return;