Add `Style/RedundantFreeze` to remove redudant `.freeze`

Since Rails 6.0 will support Ruby 2.4.1 or higher
`# frozen_string_literal: true` magic comment is enough to make string object frozen.
This magic comment is enabled by `Style/FrozenStringLiteralComment` cop.

* Exclude these files not to auto correct false positive `Regexp#freeze`
 - 'actionpack/lib/action_dispatch/journey/router/utils.rb'
 - 'activerecord/lib/active_record/connection_adapters/sqlite3_adapter.rb'

It has been fixed by https://github.com/rubocop-hq/rubocop/pull/6333
Once the newer version of RuboCop released and available at Code Climate these exclude entries should be removed.

* Replace `String#freeze` with `String#-@` manually if explicit frozen string objects are required

 - 'actionpack/test/controller/test_case_test.rb'
 - 'activemodel/test/cases/type/string_test.rb'
 - 'activesupport/lib/active_support/core_ext/string/strip.rb'
 - 'activesupport/test/core_ext/string_ext_test.rb'
 - 'railties/test/generators/actions_test.rb'

1 files changed, 2 insertions, 2 deletions

diff --git a/activerecord/lib/active_record/tasks/postgresql_database_tasks.rb b/activerecord/lib/active_record/tasks/postgresql_database_tasks.rb
index d3c85b161e..8acb11f75f 100644
--- a/activerecord/lib/active_record/tasks/postgresql_database_tasks.rb
+++ b/activerecord/lib/active_record/tasks/postgresql_database_tasks.rb
@@ -6,8 +6,8 @@ module ActiveRecord
   module Tasks # :nodoc:
     class PostgreSQLDatabaseTasks # :nodoc:
       DEFAULT_ENCODING = ENV["CHARSET"] || "utf8"
-      ON_ERROR_STOP_1 = "ON_ERROR_STOP=1".freeze
-      SQL_COMMENT_BEGIN = "--".freeze
+      ON_ERROR_STOP_1 = "ON_ERROR_STOP=1"
+      SQL_COMMENT_BEGIN = "--"
 
       delegate :connection, :establish_connection, :clear_active_connections!,
         to: ActiveRecord::Base