Use aidl interface for Widevine service.

The interface is defined in
hardware/interfaces/drm/aidl(http://go/ag/15329852).

Test: build
  m android.hardware.drm-service.widevine -j128

Test: build_and_run_all_unit_tests.sh
  for hidl tests

Test: atest VtsAidlHalDrmTargetTest

Bug: 200055138
Bug: 170964303
Change-Id: If2f2a129914436ba5cef1c46f6cb9415e12c3d1c

libwvdrmengine/aidl_include/wv_metrics.h

@@ -0,0 +1,19 @@
+// Copyright 2021 Google LLC. All Rights Reserved. This file and proprietary
+// source code may only be used and distributed under the Widevine License
+// Agreement.
+//
+// Format widevine protobuf metrics
+
+#ifndef WV_METRICS_H_
+#define WV_METRICS_H_
+
+#include <string>
+
+#include "wv_metrics.pb.h"
+
+namespace wv_metrics {
+void FormatWvCdmMetrics(const drm_metrics::WvCdmMetrics& metrics,
+                        std::string& result);
+}
+
+#endif  // WV_METRICS_H_