ART: Move JNI files to runtime/jni/ .

Test: Rely on TreeHugger.
Change-Id: I9cae11191ef1567ae9453be498882a7767285140
diff --git a/runtime/scoped_thread_state_change.cc b/runtime/scoped_thread_state_change.cc
index 6a86cc6..edbce05 100644
--- a/runtime/scoped_thread_state_change.cc
+++ b/runtime/scoped_thread_state_change.cc
@@ -19,7 +19,7 @@
 #include <type_traits>
 
 #include "base/casts.h"
-#include "java_vm_ext.h"
+#include "jni/java_vm_ext.h"
 #include "obj_ptr-inl.h"
 #include "runtime-inl.h"