Fix locale related specs (#3707)

* Use I18n.locale instead of ":en"
* Reset I18n.locale value after locale changing tests

spec/controllers/concerns/localized_spec.rb

@@ -19,6 +19,7 @@ describe ApplicationController, type: :controller do
     context 'when DEFAULT_LOCALE environment variable is set' do
       around do |example|
         ClimateControl.modify 'DEFAULT_LOCALE' => 'ca', &example.method(:run)
+        I18n.locale = I18n.default_locale
       end
 
       it 'sets language specified by ENV if preferred' do

spec/helpers/home_helper_spec.rb

@@ -3,7 +3,7 @@ require 'rails_helper'
 RSpec.describe HomeHelper, type: :helper do
   describe 'default_props' do
     it 'returns default properties according to the context' do
-      expect(helper.default_props).to eq locale: :en
+      expect(helper.default_props).to eq locale: I18n.locale
     end
   end
 end

spec/requests/localization_spec.rb

@@ -3,6 +3,10 @@
 require 'rails_helper'
 
 describe 'Localization' do
+  after(:all) do
+    I18n.locale = I18n.default_locale
+  end
+  
   it 'uses a specific region when provided' do
     headers = { 'Accept-Language' => 'zh-HK' }