Add missing includes.

Change-Id: Ib697ce44243e7cb07aee60944238e0854d82e9de
diff --git a/media/libmedia/MemoryLeakTrackUtil.cpp b/media/libmedia/MemoryLeakTrackUtil.cpp
index 66f7161..d31f721 100644
--- a/media/libmedia/MemoryLeakTrackUtil.cpp
+++ b/media/libmedia/MemoryLeakTrackUtil.cpp
@@ -18,6 +18,7 @@
 
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 #include <sys/types.h>
 #include <unistd.h>