chore: don't provision Twiml app if sid present

enterprise/app/models/enterprise/channel/twilio_sms.rb

@@ -66,6 +66,8 @@ module Enterprise::Channel::TwilioSms
   end
 
   def provision_twiml_app
+    return if twiml_app_sid.present?
+
     validate_voice_capability!
     service = ::Twilio::VoiceWebhookSetupService.new(channel: self)
     self.twiml_app_sid = service.perform

spec/enterprise/models/channel/twilio_sms_voice_spec.rb

@@ -57,6 +57,9 @@ RSpec.describe Channel::TwilioSms do
 
   describe 'provisioning on create' do
     it 'stores twiml_app_sid from the webhook setup service' do
+      stub_request(:get, %r{api.twilio.com/2010-04-01/Accounts/.*/IncomingPhoneNumbers.json})
+        .to_return(status: 200, body: { incoming_phone_numbers: [{ capabilities: { 'voice' => true } }] }.to_json,
+                   headers: { 'Content-Type' => 'application/json' })
       channel = create(:channel_twilio_sms, :with_voice, twiml_app_sid: nil)
       expect(channel.twiml_app_sid).to eq(twiml_app_sid)
     end
@@ -89,8 +92,7 @@ RSpec.describe Channel::TwilioSms do
     end
 
     it 'does not fail if Twilio API errors' do
-      error_response = instance_double(Twilio::HTTP::Response, status_code: 404, body: {})
-      allow(app_context).to receive(:delete).and_raise(Twilio::REST::RestError.new('Not found', error_response))
+      allow(app_context).to receive(:delete).and_raise(StandardError.new('Not found'))
 
       expect { channel.update!(voice_enabled: false) }.not_to raise_error
       expect(channel.reload.twiml_app_sid).to be_nil