Add Elastic watcher configs

We currently have a watcher that moves logs that have ElasticDeleteProjectWorker to its own index. These documents are visible here: https://log.gprd.gitlab.net/goto/5efa8250-02e7-11ed-b86b-d963a1a6788e

This puts the settings for this setup in version control.

When we are ultimately happy with this setup and the settings are stabilized, the next iteration of this would be moving this to the runbooks repo: https://gitlab.com/gitlab-com/gl-infra/gitlab-dedicated/sandbox/runbooks/-/tree/master/elastic/managed-objects

This closes gitlab-org/gitlab#366444 (closed)