Merge pull request #33152 from bogdanvlviv/fix-ruby-version-file

Fix Ruby version in `.ruby-version`

railties/lib/rails/generators/rails/app/templates/ruby-version.tt

-<%= "#{RUBY_ENGINE}-#{RUBY_ENGINE_VERSION}" -%>
+<%= ENV["RBENV_VERSION"] || ENV["rvm_ruby_string"] || "#{RUBY_ENGINE}-#{RUBY_ENGINE_VERSION}" -%>

railties/test/generators/app_generator_test.rb

@@ -891,9 +891,15 @@ def test_inclusion_of_ruby_version
       assert_match(/ruby '#{RUBY_VERSION}'/, content)
     end
     assert_file ".ruby-version" do |content|
+      if ENV["RBENV_VERSION"]
+        assert_match(/#{ENV["RBENV_VERSION"]}/, content)
+      elsif ENV["rvm_ruby_string"]
+        assert_match(/#{ENV["rvm_ruby_string"]}/, content)
+      else
         assert_match(/#{RUBY_ENGINE}-#{RUBY_ENGINE_VERSION}/, content)
       end
     end
+  end
 
   def test_version_control_initializes_git_repo
     run_generator [destination_root]