Cherry pick 18.4 changes to udc-widevine-dev

Get the udc-widevine-dev Android branch and oemcrypto-v18 cdm branch in
sync. The commit ID for 18.4 on oemcrypto-v18 is
a2f23a2281e5e06dc2867585bdc516fa132b6396.

Merged from go/wvgerrit/190151

Bug: 290252845
Test: WVTS tests are running and passing
Change-Id: I457332e7ca70a5b5169345e1279b3eb9f18413b6

libwvdrmengine/cdm/test/cdm_test_printers.h

@@ -0,0 +1,21 @@
+// Copyright 2018 Google LLC. All Rights Reserved. This file and proprietary
+// source code may only be used and distributed under the Widevine License
+// Agreement.
+// This file adds some print methods so that when unit tests fail, the
+// will print the name of an enumeration instead of the numeric value.
+
+#ifndef WVCDM_CDM_TEST_CDM_TEST_PRINTERS_H_
+#define WVCDM_CDM_TEST_CDM_TEST_PRINTERS_H_
+
+#include <iostream>
+#include "cdm.h"
+
+namespace widevine {
+
+void PrintTo(const Cdm::MessageType& value, ::std::ostream* os);
+void PrintTo(const Cdm::Status& value, ::std::ostream* os);
+void PrintTo(const Cdm::KeyStatus& value, ::std::ostream* os);
+
+}  // namespace widevine
+
+#endif  // WVCDM_CDM_TEST_CDM_TEST_PRINTERS_H_