fix: Fix i18n issues with help center (#6559)

app/controllers/public/api/v1/portals/base_controller.rb

@@ -0,0 +1,22 @@
+class Public::Api::V1::Portals::BaseController < PublicController
+  around_action :set_locale
+
+  private
+
+  def set_locale(&)
+    switch_locale_with_portal(&) if params[:locale].present?
+  end
+
+  def switch_locale_with_portal(&)
+    locale_without_variant = params[:locale].split('_')[0]
+    is_locale_available = I18n.available_locales.map(&:to_s).include?(params[:locale])
+    is_locale_variant_available = I18n.available_locales.map(&:to_s).include?(locale_without_variant)
+    if is_locale_available
+      @locale = params[:locale]
+    elsif is_locale_variant_available
+      @locale = locale_without_variant
+    end
+
+    I18n.with_locale(@locale, &)
+  end
+end