Shorten name of broadcast utility function

This is doing more than just validating and updating an is about to
do even more. Saying "update" is broad enough to cover the others.

app/broadcast_message/rest.py

@@ -2,14 +2,12 @@ import iso8601
 from flask import Blueprint, jsonify, request
 from notifications_utils.template import BroadcastMessageTemplate
 
+from app.broadcast_message import utils as broadcast_utils
 from app.broadcast_message.broadcast_message_schema import (
     create_broadcast_message_schema,
     update_broadcast_message_schema,
     update_broadcast_message_status_schema,
 )
-from app.broadcast_message.utils import (
-    validate_and_update_broadcast_message_status,
-)
 from app.dao.broadcast_message_dao import (
     dao_get_broadcast_message_by_id_and_service_id,
     dao_get_broadcast_messages_for_service,
@@ -162,6 +160,6 @@ def update_broadcast_message_status(service_id, broadcast_message_id):
                 status_code=400
             )
 
-    validate_and_update_broadcast_message_status(broadcast_message, new_status, updating_user)
+    broadcast_utils.update_broadcast_message_status(broadcast_message, new_status, updating_user)
 
     return jsonify(broadcast_message.serialize()), 200

app/broadcast_message/utils.py

@@ -13,7 +13,7 @@ from app.models import (
 )
 
 
-def validate_and_update_broadcast_message_status(broadcast_message, new_status, updating_user=None, api_key_id=None):
+def update_broadcast_message_status(broadcast_message, new_status, updating_user=None, api_key_id=None):
     _validate_broadcast_update(broadcast_message, new_status, updating_user)
 
     if new_status == BroadcastStatusType.BROADCASTING:

app/v2/broadcast/post_broadcast.py

@@ -6,10 +6,8 @@ from notifications_utils.template import BroadcastMessageTemplate
 from sqlalchemy.orm.exc import MultipleResultsFound
 
 from app import api_user, authenticated_service, redis_store
+from app.broadcast_message import utils as broadcast_utils
 from app.broadcast_message.translators import cap_xml_to_dict
-from app.broadcast_message.utils import (
-    validate_and_update_broadcast_message_status,
-)
 from app.dao.broadcast_message_dao import (
     dao_get_broadcast_message_by_references_and_service_id,
 )
@@ -121,7 +119,7 @@ def _cancel_or_reject_broadcast(references_to_original_broadcast, service_id):
         new_status = BroadcastStatusType.REJECTED
     else:
         new_status = BroadcastStatusType.CANCELLED
-    validate_and_update_broadcast_message_status(
+    broadcast_utils.update_broadcast_message_status(
         broadcast_message,
         new_status,
         api_key_id=api_user.id