Add includes for waitpid

(cherry picked from commit f07c5dd9ab63f2e8ba736107bd4b69bbd8829c9f)

Change-Id: I7a765fd7a3a5f8f29a703f6a591c4fd8df4ebf1c
diff --git a/tests/time_test.cpp b/tests/time_test.cpp
index 9563c78..7a2116b 100644
--- a/tests/time_test.cpp
+++ b/tests/time_test.cpp
@@ -20,6 +20,8 @@
 #include <features.h>
 #include <gtest/gtest.h>
 #include <signal.h>
+#include <sys/types.h>
+#include <sys/wait.h>
 
 #include "ScopedSignalHandler.h"