Can't upload backup to Google Cloud Platform

Summary

When Gitlab tries to upload the backup to GCP, I get an error: [fog][WARNING] Please install the google-api-client gem before using this provider. This bug exists since the release 10.1 or 10.2.

Steps to reproduce

• Add GCP as backup provider.
• Backup.

Relevant logs and/or screenshots

Dumping database ... 
Dumping PostgreSQL database gitlabhq_production ... [DONE]
done
Dumping repositories ...
[SKIPPED]
Dumping uploads ... 
[SKIPPED]
Dumping builds ... 
[SKIPPED]
Dumping artifacts ... 
[SKIPPED]
Dumping pages ... 
[SKIPPED]
Dumping lfs objects ... 
[SKIPPED]
Dumping container registry images ... 
[SKIPPED]
Creating backup archive: 1520339121_2018_03_06_10.5.1-ee_gitlab_backup.tar ... done
Uploading backup archive to remote storage sr-backup-gitlab ... [fog][WARNING] Please install the google-api-client gem before using this provider
rake aborted!
Fog::Service::NotFound: google has no storage service
/opt/gitlab/embedded/service/gitlab-rails/lib/backup/manager.rb:181:in `connect_to_remote_directory'
/opt/gitlab/embedded/service/gitlab-rails/lib/backup/manager.rb:40:in `upload'
/opt/gitlab/embedded/service/gitlab-rails/lib/backup/manager.rb:27:in `block in pack'
/opt/gitlab/embedded/service/gitlab-rails/lib/backup/manager.rb:11:in `chdir'
/opt/gitlab/embedded/service/gitlab-rails/lib/backup/manager.rb:11:in `pack'
/opt/gitlab/embedded/service/gitlab-rails/lib/tasks/gitlab/backup.rake:21:in `block (3 levels) in <top (required)>'
/opt/gitlab/embedded/bin/bundle:23:in `load'
/opt/gitlab/embedded/bin/bundle:23:in `<main>'

Caused by:
LoadError: cannot load such file -- google/api_client
/opt/gitlab/embedded/service/gitlab-rails/lib/backup/manager.rb:181:in `connect_to_remote_directory'
/opt/gitlab/embedded/service/gitlab-rails/lib/backup/manager.rb:40:in `upload'
/opt/gitlab/embedded/service/gitlab-rails/lib/backup/manager.rb:27:in `block in pack'
/opt/gitlab/embedded/service/gitlab-rails/lib/backup/manager.rb:11:in `chdir'
/opt/gitlab/embedded/service/gitlab-rails/lib/backup/manager.rb:11:in `pack'
/opt/gitlab/embedded/service/gitlab-rails/lib/tasks/gitlab/backup.rake:21:in `block (3 levels) in <top (required)>'
/opt/gitlab/embedded/bin/bundle:23:in `load'
/opt/gitlab/embedded/bin/bundle:23:in `<main>'
Tasks: TOP => gitlab:backup:create
(See full trace by running task with --trace)

Results of GitLab environment info

Expand for output related to the GitLab environment info

System information
System:		Debian 8.10
Proxy:		no
Current User:	git
Using RVM:	no
Ruby Version:	2.3.6p384
Gem Version:	2.6.13
Bundler Version:1.13.7
Rake Version:	12.3.0
Redis Version:	3.2.11
Git Version:	2.14.3
Sidekiq Version:5.0.5
Go Version:	unknown

GitLab information
Version:	10.5.3-ee
Revision:	e847016
Directory:	/opt/gitlab/embedded/service/gitlab-rails
DB Adapter:	postgresql
DB Version:	9.6.5
URL:		https://gitlab.stanley-robotics.xyz
HTTP Clone URL:	https://gitlab.stanley-robotics.xyz/some-group/some-project.git
SSH Clone URL:	git@gitlab.stanley-robotics.xyz:some-group/some-project.git
Elasticsearch:	no
Geo:		no
Using LDAP:	no
Using Omniauth:	yes
Omniauth Providers: google_oauth2

GitLab Shell
Version:	6.0.3
Repository storage paths:
- default: 	/var/opt/gitlab/git-data/repositories
Hooks:		/opt/gitlab/embedded/service/gitlab-shell/hooks
Git:		/opt/gitlab/embedded/bin/git