old_contents: from corehq.apps.sms.api import incoming as incoming_sms
  from corehq.apps.twilio.models import TwilioBackend
  from django.http import HttpResponse, HttpResponseBadRequest
  from django.views.decorators.csrf import csrf_exempt
  
  EMPTY_RESPONSE = """<?xml version="1.0" encoding="UTF-8" ?>
  <Response />"""
  
  @csrf_exempt
  def sms_in(request):
      if request.method == "POST":
          message_sid = request.POST.get("MessageSid")
          account_sid = request.POST.get("AccountSid")
          from_ = request.POST.get("From")
          to = request.POST.get("To")
          body = request.POST.get("Body")
          incoming_sms(
              from_,
              body,
              TwilioBackend.get_api_id(),
              backend_message_id=message_sid
          )
          return HttpResponse(EMPTY_RESPONSE)
      else:
          return HttpResponseBadRequest("POST Expected")
  
  
new_contents: from corehq.apps.sms.api import incoming as incoming_sms
  from corehq.apps.twilio.models import TwilioBackend
  from django.http import HttpResponse, HttpResponseBadRequest
  from django.views.decorators.csrf import csrf_exempt
  
  EMPTY_RESPONSE = """<?xml version="1.0" encoding="UTF-8" ?>
  <Response></Response>"""
  
  @csrf_exempt
  def sms_in(request):
      if request.method == "POST":
          message_sid = request.POST.get("MessageSid")
          account_sid = request.POST.get("AccountSid")
          from_ = request.POST.get("From")
          to = request.POST.get("To")
          body = request.POST.get("Body")
          incoming_sms(
              from_,
              body,
              TwilioBackend.get_api_id(),
              backend_message_id=message_sid
          )
          return HttpResponse(EMPTY_RESPONSE)
      else:
          return HttpResponseBadRequest("POST Expected")
  
  
subject: Update empty response