Enable before_committed callbacks on all records

This doesn't really affect us because we don't use `before_committed`
callbacks (and neither do any of our dependencies), so we're using the
new default value.

config/initializers/new_framework_defaults_7_1.rb

@@ -178,7 +178,7 @@ Rails.application.config.precompile_filter_parameters = true
 # The previous behavior was to only run the callbacks on the first copy of a record
 # if there were multiple copies of the same record enrolled in the transaction.
 #++
-# Rails.application.config.active_record.before_committed_on_all_records = true
+Rails.application.config.active_record.before_committed_on_all_records = true
 
 ###
 # Disable automatic column serialization into YAML.