ART: Move JNI files to runtime/jni/ .

Test: Rely on TreeHugger.
Change-Id: I9cae11191ef1567ae9453be498882a7767285140
diff --git a/runtime/native/java_lang_reflect_Field.cc b/runtime/native/java_lang_reflect_Field.cc
index 13275d9..e0afbee 100644
--- a/runtime/native/java_lang_reflect_Field.cc
+++ b/runtime/native/java_lang_reflect_Field.cc
@@ -26,7 +26,7 @@
 #include "common_throws.h"
 #include "dex/dex_file-inl.h"
 #include "dex/dex_file_annotations.h"
-#include "jni_internal.h"
+#include "jni/jni_internal.h"
 #include "mirror/class-inl.h"
 #include "mirror/field-inl.h"
 #include "native_util.h"