Add installation type to backup information file
Closes: https://gitlab.com/charts/gitlab/issues/808
Corresponding MR in CE - https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/22150
Edited by Balasankar 'Balu' C
Closes: https://gitlab.com/charts/gitlab/issues/808
Corresponding MR in CE - https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/22150