Use correct retry mechanism in tags

This replaces wrap_db_retry with
neutron.db.api.retry_if_session_inactive() in the tags
plugin.

wrap_db_retry is missing a bunch of exception types we
can encounter and are expected to retry in normal database
operations in Neutron (e.g. staledataerror in the bug report).

This patch doesn't include a unit test because there is already
quite a bit of coverage ensuring the decorator handles these types
of exceptions.

Closes-Bug: #1673243
Change-Id: I65b10ee54301401cd4525152a82a604ac8744582
(cherry picked from commit 44b6fcb4d2)

neutron/services/tag/tag_plugin.py

@@ -15,7 +15,6 @@
 import functools
 
 from neutron_lib.plugins import directory
-from oslo_db import api as oslo_db_api
 from oslo_db import exception as db_exc
 from oslo_log import helpers as log_helpers
 from sqlalchemy.orm import exc
@@ -75,9 +74,7 @@ class TagPlugin(common_db_mixin.CommonDbMixin, tag_ext.TagPluginBase):
             raise tag_ext.TagNotFound(tag=tag)
 
     @log_helpers.log_method_call
-    @oslo_db_api.wrap_db_retry(
-        max_retries=db_api.MAX_RETRIES,
-        exception_checker=lambda e: isinstance(e, db_exc.DBDuplicateEntry))
+    @db_api.retry_if_session_inactive()
     def update_tags(self, context, resource, resource_id, body):
         with db_api.context_manager.writer.using(context):
             # We get and do all operations with objects in one session