Merge branch 'feature/sm/35954-create-kubernetes-cluster-on-gke-from-k8s-service' of https://gitlab.com/gitlab-org/gitlab-ce into feature/sm/35954-create-kubernetes-cluster-on-gke-from-k8s-service

Adjust toggle status
Add confirmation box
Adds permissions checks

Adds polling function

Merge branch 'feature/sm/35954-create-kubernetes-cluster-on-gke-from-k8s-service' of https://gitlab.com/gitlab-org/gitlab-ce into feature/sm/35954-create-kubernetes-cluster-on-gke-from-k8s-service

* 'feature/sm/35954-create-kubernetes-cluster-on-gke-from-k8s-service' of https://gitlab.com/gitlab-org/gitlab-ce:
  PollingInterval, rename to gke_clusters, has_one :cluster
  Use expires_in for access_token validation

Adds new line at the end of files

[ci skip]

Fix duplicate key errors in PostDeployMigrateUserExternalMailData migration

Closes #38246

See merge request gitlab-org/gitlab-ce!14460

`email_provider` by default is NULL, and if a user had not logged the
value would remain NULL. Upgrading to GitLab 10.0 would lead to a
PG::UniqueViolation because the post-deploy migration would attempt
to reinsert the entry because the NULL comparison between
`users.email_provider` and `user_synced_attributes_metadata.email_provider`
would never match.

Closes #38246

Workaround for n+1 in Projects::TreeController#show

Closes #38171

See merge request gitlab-org/gitlab-ce!14455

Allow the git circuit breaker to correctly handle missing repository storages

Closes #36549

See merge request gitlab-org/gitlab-ce!14417

fix typo in icons section

See merge request gitlab-org/gitlab-ce!14444

Workaround for #38259

See merge request gitlab-org/gitlab-ce!14453

Inform user that current shared projects will remain shared

Closes #38220

See merge request gitlab-org/gitlab-ce!14441