Fix a false positive for Lint/UselessAccessModifier when using same access modifier inside and outside the included block

[ydah]

This PR is fix a false positive for Lint/UselessAccessModifier when using same access modifier inside and outside the included block.

If an included block is used within a class, as shown below, I think it should not be a violation even if the same access modifier is used inside and outside the included block.

class SomeClass
  included do
    private
    def foo; end
  end
  private
  def bar; end
end

---

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• The PR relates to only one subject with a clear title and description in grammatically correct, complete sentences.
• Wrote good commit messages.
• [-] Commit message starts with [Fix #issue-number] (if the related issue exists).
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• Squashed related commits together.
• Added tests.
• Ran bundle exec rake default. It executes all tests and runs RuboCop on its own code.
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[koic]

The included block is a ActiveSupport::Concern's method, right? RuboCop core is for vanilla Ruby. If Rails content will be included in the core, it may be better to include active_support_extensions_enabled? (ActiveSupportExtensionsEnabled config) as a condition.
https://docs.rubocop.org/rubocop/configuration.html#enable-checking-active-support-extensions

Style/HashExcept may be a reference for implementation.

[ydah]

The included block is a ActiveSupport::Concern's method, right? RuboCop core is for vanilla Ruby. If Rails content will be included in the core, it may be better to include active_support_extensions_enabled? (ActiveSupportExtensionsEnabled config) as a condition. https://docs.rubocop.org/rubocop/configuration.html#enable-checking-active-support-extensions

Style/HashExcept may be a reference for implementation.

I was not aware of active_support_extensions_enabled?. Thanks for letting me know about it. I updated this PR.

[koic]

There may be a better way, but since there are no new parameters added, so there will be no impact on API compatibility. I'm going to merge this PR. Thank you.