DrmManager: record usage with libmediametrics

Bug: 134789967
Test: dumpsys media.metrics
Change-Id: I153244203aef0d8b9034efe4ff26f42028aadd7c
diff --git a/drm/drmserver/DrmManager.h b/drm/drmserver/DrmManager.h
index 26222bc..75fc1a8 100644
--- a/drm/drmserver/DrmManager.h
+++ b/drm/drmserver/DrmManager.h
@@ -143,6 +143,9 @@
 
     bool canHandle(int uniqueId, const String8& path);
 
+    void reportEngineMetrics(const char func[],
+            const String8& plugInId, const String8& mimeType = String8(""));
+
 private:
     enum {
         kMaxNumUniqueIds = 0x1000,