ART: Move JNI files to runtime/jni/ .

Test: Rely on TreeHugger.
Change-Id: I9cae11191ef1567ae9453be498882a7767285140
diff --git a/runtime/arch/stub_test.cc b/runtime/arch/stub_test.cc
index 4be4b12..78516e3 100644
--- a/runtime/arch/stub_test.cc
+++ b/runtime/arch/stub_test.cc
@@ -24,7 +24,7 @@
 #include "common_runtime_test.h"
 #include "entrypoints/quick/quick_entrypoints_enum.h"
 #include "imt_conflict_table.h"
-#include "jni_internal.h"
+#include "jni/jni_internal.h"
 #include "linear_alloc.h"
 #include "mirror/class-inl.h"
 #include "mirror/string-inl.h"