Added workaround passing empty arg array for proxy invocation.

This recreates old Dalvik behavior for older target sdk versions,
but will still pass null for newer ones.

Bug: 13247236

(cherry picked from commit 01d5a146e20660bd06f026c16f19ec080f8fdd7b)

Change-Id: I911889cf559ad8d9f37ea9be3929387c86446851
diff --git a/runtime/runtime.cc b/runtime/runtime.cc
index 361070c..68b10cc 100644
--- a/runtime/runtime.cc
+++ b/runtime/runtime.cc
@@ -141,7 +141,8 @@
       null_pointer_handler_(nullptr),
       suspend_handler_(nullptr),
       stack_overflow_handler_(nullptr),
-      verify_(false) {
+      verify_(false),
+      target_sdk_version_(0) {
   for (int i = 0; i < Runtime::kLastCalleeSaveType; i++) {
     callee_save_methods_[i] = nullptr;
   }