Turn International SMS back off by default

Fixes CNVS-26271

Test plan:
 - Ensure that the International SMS feature flag is off by
   default
 - Ensure that you don't have the option to choose a country when
   adding an SMS phone number to your profile

Change-Id: I8e536b4252256b4aae299b444511eab7771c3e11
Reviewed-on: https://gerrit.instructure.com/69825
Reviewed-by: Matthew Wheeler <mwheeler@instructure.com>
Tested-by: Jenkins
QA-Review: Heath Hales <hhales@instructure.com>
Product-Review: Alex Boyd <aboyd@instructure.com>

lib/feature.rb

@@ -387,7 +387,7 @@ END
       display_name: -> { I18n.t('International SMS') },
       description: -> { I18n.t('Allows users with international phone numbers to receive text messages from Canvas.') },
       applies_to: 'RootAccount',
-      state: 'on',
+      state: 'hidden',
       root_opt_in: true
     },
     'international_sms_from_recipient_country' => {

spec/models/message_spec.rb

@@ -267,6 +267,7 @@ describe Message do
     context 'SMS' do
       before :once do
         user_model
+        @user.account.enable_feature!(:international_sms)
       end
 
       before do

spec/selenium/profile_spec.rb

@@ -80,6 +80,7 @@ describe "profile" do
     end
 
     it "should add a new email address on profile settings page" do
+      @user.account.enable_feature!(:international_sms)
       notification_model(:category => 'Grading')
       notification_policy_model(:notification_id => @notification.id)
 
@@ -161,6 +162,7 @@ describe "profile" do
     end
 
     it "should add another contact method - sms" do
+      @user.account.enable_feature!(:international_sms)
       test_cell_number = '8017121011'
       get "/profile/settings"
       f('.add_contact_link').click