native: Cleanup jni usage code

Make the C++ signature consistent with the JNI descriptor by using the
same type as the descriptor whenever possible.

e.g. "()Ljava/lang/String;" should actually be "jstring fn(JNIEnv*,jobject)"
instead of "jobject fn(JNIEnv*,jobject)".

Bug: 35325126
Change-Id: I72318525fc3b18b013b8d6fa604d8dd6b5dd4400
Test: make -j32 test-art-host  # and also manually that it boots
diff --git a/runtime/native/java_lang_reflect_Array.cc b/runtime/native/java_lang_reflect_Array.cc
index 12d4008..d28f741 100644
--- a/runtime/native/java_lang_reflect_Array.cc
+++ b/runtime/native/java_lang_reflect_Array.cc
@@ -31,7 +31,7 @@
 namespace art {
 
 static jobject Array_createMultiArray(
-    JNIEnv* env, jclass, jclass javaElementClass, jobject javaDimArray) {
+    JNIEnv* env, jclass, jclass javaElementClass, jintArray javaDimArray) {
   ScopedFastNativeObjectAccess soa(env);
   DCHECK(javaElementClass != nullptr);
   StackHandleScope<2> hs(soa.Self());