[native_doc_dartifier] Adding some End to End tests

[marshelino-maged]

Here is a link to my fork's PR to show the CI output: https://github.com/marshelino-maged/native/pull/5
Related to #2343
Adding some end-to-end tests that test:

• The initialization and call to an inner Java class inside some outer class.
• The use of strings correctly using toJString() and toDartString()
• The use of identifiers that start with '_'
• The use of identifiers that have some '$'

---

• I’ve reviewed the contributor guide and applied the relevant portions to this PR.

[github-actions]

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// Copyright (c) 2025, the Dart project authors. Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

Files
pkgs/native_doc_dartifier/tool/compile_java.dart

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pkgs/jni/lib/src/third_party/generated_bindings.dart
pkgs/native_doc_dartifier/lib/native_doc_dartifier.dart
pkgs/native_doc_dartifier/lib/src/native_doc_dartifier_base.dart
pkgs/objective_c/lib/src/ns_input_stream.dart

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[marshelino-maged]

A small change in tests ... makes all Java snippets used in tests return a boolean value, then in runtime_test.dart only checks if functions return True.

This makes the runtime_test.dart to be low coupled with the java_snippets.dart

[HosseinYousefi]

LGTM

[HosseinYousefi]

Please update the branch with the latest changes.

[marshelino-maged]

Please update the branch with the latest changes.

Done