Add additional stack space to account for the dalvik native stack size

Change-Id: Iede575cf5b2185f374c0617208e924cc88cdba6c
diff --git a/src/thread.h b/src/thread.h
index 4f43473..c5695cf 100644
--- a/src/thread.h
+++ b/src/thread.h
@@ -92,7 +92,7 @@
   static const size_t kStackOverflowReservedBytes = 8 * KB;
 #endif
 
-  static const size_t kDefaultStackSize = 128 * KB;
+  static const size_t kDefaultStackSize = 16 * KB;
 
   class StackVisitor {
    public: