Refactor oemcrypto mock into stand alone reference code

Merge from Widevine repo of http://go/wvgerrit/46204
Refactor utility code - split the mock, step 1

Merge from Widevine repo of http://go/wvgerrit/46205
Move some OEMCrypto types to common header - split the mock, step 2

Merge from Widevine repo of http://go/wvgerrit/46206
Split mock into two -- step 3

Merge from Widevine repo of http://go/wvgerrit/47460
Split the mock into two -- step 3.5

The CL moves several files used by oemcrypto and cdm into a common
subdirectory, so that it may more easily be shared with partners.

The CORE_DISALLOW_COPY_AND_ASSIGN macro was moved to its own header in
the util/include directory.

This CL removes some references to the mock from other code, and puts
some constants and types, such as the definition of the keybox, into a
header in oemcrypto.

Test: tested as part of http://go/ag/4674759
bug: 76393338
Change-Id: I75b4bde7062ed8ee572c97ebc2f4da018f4be0c9

libwvdrmengine/oemcrypto/ref/src/oem_cert.h

@@ -0,0 +1,21 @@
+// This header is used to access the OEM certificate if one is in use.
+#ifndef OEM_CERT_H_
+#define OEM_CERT_H_
+
+#include <stddef.h>
+#include <stdint.h>
+
+namespace wvoec_ref {
+
+// Refer to the following in main modules
+extern const uint32_t kOEMSystemId;
+
+extern const uint8_t* kOEMPrivateKey;
+extern const uint8_t* kOEMPublicCert;
+
+extern const size_t kOEMPrivateKeySize;
+extern const size_t kOEMPublicCertSize;
+
+}  // namespace wvoec_ref
+
+#endif  // OEM_CERT_H_