Issue with rendering .md and .ipynb files on Chrome browser

[abhishek9sharma]

Does this issue occur when all extensions are disabled?: Yes/No

• VS Code Version: openvscode-server-v1.78.0-linux-x64
• OS Version: ubuntu:20.04

Steps to Reproduce:

1. Could not reproduce on a local Docker machine

We currently use Theia based Docker container in our organization to allow users to use a code editor via the browser. We are currently looking at introducing openvscode-server based containers. We were able to install the openvscode-server-v1.78.0-linux-x64 on a Dockerfile and run it on our infra.

• However while using Chrome browser we are seeing issues with rendering .md and .ipynb files. The rendering does not suceed and we are seeing cross-origin-subframe erros on Chrome. A snapshot of errors is provided below
  
• On theia browser the rendering works fine for both .md and .ipynb files. We did set the value THEIA_WEBVIEW_EXTERNAL_ENDPOINT to {{hostname}}. Is their a similar variable we need to set here?