Move updating user validation out of validate_and_update_broadcast_message_status

As only 1 of 2 functions calling it needs that check, it's better
to perform it inside that 1 function.

app/broadcast_message/rest.py

@@ -42,15 +42,7 @@ def _parse_nullable_datetime(dt):
     return dt
 
 
-def validate_and_update_broadcast_message_status(broadcast_message, new_status, updating_user, from_api=False):
-    if updating_user not in broadcast_message.service.users:
-        #  we allow platform admins to cancel broadcasts, and we don't check user if request was done via API
-        if not from_api and not (new_status == BroadcastStatusType.CANCELLED and updating_user.platform_admin):
-            raise InvalidRequest(
-                f'User {updating_user.id} cannot update broadcast_message {broadcast_message.id} from other service',
-                status_code=400
-            )
-
+def validate_and_update_broadcast_message_status(broadcast_message, new_status, updating_user):
     if new_status not in BroadcastStatusType.ALLOWED_STATUS_TRANSITIONS[broadcast_message.status]:
         raise InvalidRequest(
             f'Cannot move broadcast_message {broadcast_message.id} from {broadcast_message.status} to {new_status}',
@@ -206,6 +198,14 @@ def update_broadcast_message_status(service_id, broadcast_message_id):
     new_status = data['status']
     updating_user = get_user_by_id(data['created_by'])
 
+    if updating_user not in broadcast_message.service.users:
+        #  we allow platform admins to cancel broadcasts, and we don't check user if request was done via API
+        if not (new_status == BroadcastStatusType.CANCELLED and updating_user.platform_admin):
+            raise InvalidRequest(
+                f'User {updating_user.id} cannot update broadcast_message {broadcast_message.id} from other service',
+                status_code=400
+            )
+
     validate_and_update_broadcast_message_status(broadcast_message, new_status, updating_user)
 
     return jsonify(broadcast_message.serialize()), 200

app/v2/broadcast/post_broadcast.py

@@ -111,7 +111,7 @@ def _cancel_or_reject_broadcast(references_to_original_broadcast, service_id):
             message="Broadcast message reference and service id didn't match with any existing broadcasts",
             status_code=404,
         )
-    # do we need to check if service is active?
+
     if broadcast_message.status == BroadcastStatusType.PENDING_APPROVAL:
         new_status = BroadcastStatusType.REJECTED
     else:
@@ -119,8 +119,7 @@ def _cancel_or_reject_broadcast(references_to_original_broadcast, service_id):
     validate_and_update_broadcast_message_status(
         broadcast_message,
         new_status,
-        updating_user=None,
-        from_api=True
+        updating_user=None
     )
     return broadcast_message