Merge branch 'add-installation-type-backup-information' into 'master'

Add installation type to backup information file

See merge request gitlab-org/gitlab-ce!22150

changelogs/unreleased/add-installation-type-backup-information.yml

+---
+title: Add installation type to backup information file
+merge_request: 22150
+author:
+type: changed

lib/backup/manager.rb

@@ -243,6 +243,7 @@ module Backup
         backup_created_at: Time.now,
         gitlab_version: Gitlab::VERSION,
         tar_version: tar_version,
+        installation_type: Gitlab::INSTALLATION_TYPE,
         skipped: ENV["SKIP"]
       }
     end