Replace scoped_ptr With std::unique_ptr

(This is a merge of http://go/wvgerrit/65782)

We have had our own scoped_ptr implementation that is used throughout
the codebase. Now that we support C++11, we can replace these with
std::unique_ptr.

Doing this replacement exposed a few places where the two were not
interchangeable. OEMCrypto Ref was doing some unsafe things with passing
scoped_ptrs to functions and has been updated to use move semantics. And
a few constructors were explicitly constructing a scoped_ptr with NULL,
which is ambiguous with std::unique_ptr. These have been replaced with
default constructor calls.

Bug: 111851141
Test: CE CDM Unit Tests
Test: Android Unit Tests
Change-Id: I37d6d7aad4906709381c74f0c5439f826d2be768

libwvdrmengine/oemcrypto/ref/src/oemcrypto_auth_ref.h

@@ -8,6 +8,7 @@
 #define OEMCRYPTO_AUTH_REF_H_
 
 #include <stdint.h>
+#include <memory>
 #include <vector>
 
 #include <openssl/rsa.h>
@@ -17,7 +18,6 @@
 #include "oemcrypto_key_ref.h"
 #include "oemcrypto_keybox_ref.h"
 #include "oemcrypto_rsa_key_shared.h"
-#include "oemcrypto_scoped_ptr.h"
 #include "oemcrypto_types.h"
 
 namespace wvoec_ref {