Bump unauthenticated session time from 1 hour to 2 hours

Users who have their system clocks configured inconsistently due to Daylight
Savings may see a GitLab session cookie that immediately expires, resulting in
a 422 error. To avoid these errors, we can bump the unauthenticated session
time from 1 hour to 2 hours so they have time to login and get the default 7-day
session.

Closes #50393

changelogs/unreleased/sh-bump-unauth-expiration.yml

+---
+title: Bump unauthenticated session time from 1 hour to 2 hours
+merge_request: 21453
+author:
+type: other

config/initializers/1_settings.rb

@@ -141,7 +141,7 @@ Settings.gitlab['default_projects_features'] ||= {}
 Settings.gitlab['webhook_timeout'] ||= 10
 Settings.gitlab['max_attachment_size'] ||= 10
 Settings.gitlab['session_expire_delay'] ||= 10080
-Settings.gitlab['unauthenticated_session_expire_delay'] ||= 1.hour.to_i
+Settings.gitlab['unauthenticated_session_expire_delay'] ||= 2.hours.to_i
 Settings.gitlab.default_projects_features['issues']             = true if Settings.gitlab.default_projects_features['issues'].nil?
 Settings.gitlab.default_projects_features['merge_requests']     = true if Settings.gitlab.default_projects_features['merge_requests'].nil?
 Settings.gitlab.default_projects_features['wiki']               = true if Settings.gitlab.default_projects_features['wiki'].nil?