Remove with_lock_retries from RenameTableHelpers

Also update docs to suggest using lock-retries at the
migration level.

db/migrate/20210531053916_rename_instance_statistics_measurements.rb

 # frozen_string_literal: true
 
-class RenameInstanceStatisticsMeasurements < ActiveRecord::Migration[6.0]
-  include Gitlab::Database::MigrationHelpers
+class RenameInstanceStatisticsMeasurements < Gitlab::Database::Migration[1.0]
+  enable_lock_retries!
 
   def up
     rename_table_safely(:analytics_instance_statistics_measurements, :analytics_usage_trends_measurements)

db/migrate/20210621043337_rename_services_to_integrations.rb

 # frozen_string_literal: true
 
-class RenameServicesToIntegrations < ActiveRecord::Migration[6.1]
-  include Gitlab::Database::MigrationHelpers
+class RenameServicesToIntegrations < Gitlab::Database::Migration[1.0]
   include Gitlab::Database::SchemaHelpers
 
+  enable_lock_retries!
+
   # Function and trigger names match those migrated in:
   # - https://gitlab.com/gitlab-org/gitlab/-/merge_requests/49916
   # - https://gitlab.com/gitlab-org/gitlab/-/merge_requests/51852

doc/development/database/rename_database_tables.md

@@ -60,6 +60,8 @@ Consider the next release as "Release N.M".
 Execute a standard migration (not a post-migration):
 
 ```ruby
+  enable_lock_retries!
+
   def up
     rename_table_safely(:issues, :tickets)
   end

lib/gitlab/database/rename_table_helpers.rb

@@ -4,27 +4,27 @@ module Gitlab
   module Database
     module RenameTableHelpers
       def rename_table_safely(old_table_name, new_table_name)
-        with_lock_retries do
+        transaction do
           rename_table(old_table_name, new_table_name)
           execute("CREATE VIEW #{old_table_name} AS SELECT * FROM #{new_table_name}")
         end
       end
 
       def undo_rename_table_safely(old_table_name, new_table_name)
-        with_lock_retries do
+        transaction do
           execute("DROP VIEW IF EXISTS #{old_table_name}")
           rename_table(new_table_name, old_table_name)
         end
       end
 
       def finalize_table_rename(old_table_name, new_table_name)
-        with_lock_retries do
+        transaction do
           execute("DROP VIEW IF EXISTS #{old_table_name}")
         end
       end
 
       def undo_finalize_table_rename(old_table_name, new_table_name)
-        with_lock_retries do
+        transaction do
           execute("CREATE VIEW #{old_table_name} AS SELECT * FROM #{new_table_name}")
         end
       end