ART: Move JNI files to runtime/jni/ .

Test: Rely on TreeHugger.
Change-Id: I9cae11191ef1567ae9453be498882a7767285140
diff --git a/runtime/native/java_lang_reflect_Method.cc b/runtime/native/java_lang_reflect_Method.cc
index 4355c06..2503b3c 100644
--- a/runtime/native/java_lang_reflect_Method.cc
+++ b/runtime/native/java_lang_reflect_Method.cc
@@ -23,7 +23,7 @@
 #include "class_linker-inl.h"
 #include "class_linker.h"
 #include "dex/dex_file_annotations.h"
-#include "jni_internal.h"
+#include "jni/jni_internal.h"
 #include "mirror/class-inl.h"
 #include "mirror/object-inl.h"
 #include "mirror/object_array-inl.h"