Sync gitaly config with the settings from omnibus
Summary
Our gitaly settings available for users to change here in the chart are missing quite a few of the settings from omnibus.
For example, prometheus related settings, logging related settings, concurrency settings, and advanced ruby settings all exist in omnibus: https://gitlab.com/gitlab-org/omnibus-gitlab/blob/master/files/gitlab-cookbooks/gitaly/templates/default/gitaly-config.toml.erb
but not the charts: https://gitlab.com/charts/gitlab/blob/master/charts/gitlab/charts/gitaly/templates/configmap.yml
Most of those settings should be available here in the chart as well.