place mediametricsservice headers in a subdirectory

consumers will now say <mediametrics/xxx.h>

Bug: 201944383
Test: build
Change-Id: Idc2bce16d9ddde43b9c118b85f1014f16b98e65b
diff --git a/services/mediametrics/tests/mediametrics_tests.cpp b/services/mediametrics/tests/mediametrics_tests.cpp
index 102700a..bc7b47b 100644
--- a/services/mediametrics/tests/mediametrics_tests.cpp
+++ b/services/mediametrics/tests/mediametrics_tests.cpp
@@ -17,19 +17,18 @@
 #define LOG_TAG "mediametrics_tests"
 #include <utils/Log.h>
 
-#include "MediaMetricsService.h"
 
 #include <stdio.h>
 #include <unordered_set>
 
 #include <gtest/gtest.h>
 #include <media/MediaMetricsItem.h>
+#include <mediametricsservice/AudioTypes.h>
+#include <mediametricsservice/MediaMetricsService.h>
+#include <mediametricsservice/StringUtils.h>
+#include <mediametricsservice/ValidateId.h>
 #include <system/audio.h>
 
-#include "AudioTypes.h"
-#include "StringUtils.h"
-#include "ValidateId.h"
-
 using namespace android;
 
 static size_t countNewlines(const char *s) {