Add git_two_factor_session_expiry column to application_settings table

This change  adds a new column named
`git_two_factor_session_expiry` to the
`application_settings` table.

changelogs/unreleased/296669-migration-support-customizable-timeouts-for-git-cli-2fa.yml

+---
+title: Add git_two_factor_session_expiry column to application_settings table
+merge_request: 52761
+author:
+type: added

db/migrate/20210128044930_add_git_two_factor_session_expiry_to_application_settings.rb

+# frozen_string_literal: true
+
+class AddGitTwoFactorSessionExpiryToApplicationSettings < ActiveRecord::Migration[6.0]
+  DOWNTIME = false
+
+  def change
+    add_column :application_settings, :git_two_factor_session_expiry, :integer, default: 15, null: false
+  end
+end

db/schema_migrations/20210128044930

+6164ef91c60bd614310cbda6ad8ab1a205cae17c4d037fafa89eaf95d06323e4
\ No newline at end of file

db/structure.sql

@@ -9411,6 +9411,7 @@ CREATE TABLE application_settings (
     invisible_captcha_enabled boolean DEFAULT false NOT NULL,
     container_registry_cleanup_tags_service_max_list_size integer DEFAULT 200 NOT NULL,
     enforce_ssh_key_expiration boolean DEFAULT false NOT NULL,
+    git_two_factor_session_expiry integer DEFAULT 15 NOT NULL,
     CONSTRAINT app_settings_container_reg_cleanup_tags_max_list_size_positive CHECK ((container_registry_cleanup_tags_service_max_list_size >= 0)),
     CONSTRAINT app_settings_registry_exp_policies_worker_capacity_positive CHECK ((container_registry_expiration_policies_worker_capacity >= 0)),
     CONSTRAINT check_17d9558205 CHECK ((char_length((kroki_url)::text) <= 1024)),