fix(tool-vnc): Fallback to google-chrome from ungoogled_chromium

[axonasif]

Description

#872 (comment)

Related Issue(s)

Fixes #872

How to test

I pushed the image to my personal docker account and using here for testing, so you could:

• Create a new workspace from here: https://github.com/axonasif/test/tree/vnc_test
• Run gp preview $(gp url 6080) --external && chromium --start-fullscreen google.com
  • It should not display the welcome screen
  • It should not prompt to set itself as the default browser.

Release Notes

fix workspace-full-vnc ungoogled_chromium regression

Documentation

[gitpod-io]

[gitpod-staging]