Filter out on-prem requests to the main Highlight project

[ccschmitz]

We are seeing a lot of data for projects that are sending to the same project ID as the main Highlight project. We should filter out data from other projects. Basically, filter out anything where on-prem=true, but maybe this is something we want to do during ingest.

Should also consider updating the default OTLP endpoints so they don't point to Highlight for on prem deploys.