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_test_data.h

@@ -716,6 +716,8 @@ static const uint8_t kTestKeyRSAEuler_2048[] = {
     0x33, 0xe0, 0xdb, 0x03,
 };
 
+static const uint8_t kTestSandbox[] = { 0x01, 0x02, 0x03 };
+
 }  // namespace wvoec
 
 #endif  // CDM_OEC_TEST_DATA_H_