Manual test run on Linux for 0.23.x w/ Chromium 69 (BETA Channel)

[kjozwiak]

Per release specialty tests

• Allow for different default search engines based on region. (#14647)

Installer

• Check that installer is close to the size of last release.
• Check signature: If OS Run spctl --assess --verbose /Applications/Brave.app/ and make sure it returns accepted. If Windows right click on the installer exe and go to Properties, go to the Digital Signatures tab and double click on the signature. Make sure it says "The digital signature is OK" in the popup window.
• Check Brave, muon, and libchromiumcontent version in about:brave and make sure it is EXACTLY as expected.

Update tests

• Test that updating using BRAVE_UPDATE_VERSION=0.8.3 env variable works correctly.
• Test that using BRAVE_ENABLE_PREVIEW_UPDATES=TRUE env variable works and prompts for preview build updates.

[srirambv]

Closing in favour of #15189 . Issue #14647 added to #15189 for re-verification