Default headless flag added for ChromiumHeadless and ChromeCDP

[ashishislive]

This change address issue for chrome headless:

Old Headless mode has been removed from the Chrome binary. Please use the new Headless mode (https://developer.chrome.com/docs/chromium/new-headless) or the chrome-headless-shell which is a standalone implementation of the old Headless mode (https://developer.chrome.com/blog/chrome-headless-shell).