Support Elastic Search on Gitlab Hosted

A customer requested this: https://gitlab.zendesk.com/agent/tickets/57928 and stated:

it was the main factor in our decision.

Making a record here so we can gauge demand and consider adding this to GitLab Hosted.

We are currently using GitHost with EE and the missing Elasticsearch support will probably cause us to move from GitHost if this doesn't become supported soon. Thanks.

Another customer requested this here:

https://gitlab.zendesk.com/agent/tickets/80625

Perhaps the simplest way is to add a way to do this on the admin interface? https://gitlab.com/gitlab-org/gitlab-ee/issues/3072