Fix VNDK Compilation Errors

VNDK restrictions doesn't includes standard headers by
default, add them explicitly.

Change-Id: Icafac6f07fcdf58fccaabde8d472509090fb3e6f
diff --git a/visualizer/offload_visualizer.c b/visualizer/offload_visualizer.c
index 05537ec..a9664b6 100644
--- a/visualizer/offload_visualizer.c
+++ b/visualizer/offload_visualizer.c
@@ -23,6 +23,8 @@
 #include <time.h>
 #include <sys/prctl.h>
 #include <dlfcn.h>
+#include <pthread.h>
+#include <unistd.h>
 
 #include <cutils/list.h>
 #include <cutils/log.h>