Remove new "Tab bar" feature on Android

🐞 Bug Report

We should investigate if we want the new "Tab bar" feature introduced by moz sometime since 140. It defaults to off but is available as a setting under Settings -> Customize -> "Show tab bar".

While it might be a nice feature for some users, it will also reduce the screen height which is fingerprint-able. Following #31951 (closed), I think it would make sense to disable.

image.png

User impact

Fingerprint-ability is high impact. User experience is maybe low or medium since it is a new feature that the user needs to opt-in to so I wouldn't expect that many people to be using it.

Bookkeeping

  • Browser version:
  • Browser channel:
    • Release
    • Alpha
    • Nightly
  • Distribution method:
    • Installer/archive from torproject.org
    • tor-browser-launcher
    • homebrew
    • other (please specify):
  • Operating System:
    • Windows
      • Version:
    • macOS
      • Version:
    • Linux
      • Distribution + Version:
      • Desktop Environment + Version:
    • Android
      • Version:
      • Device:
    • Tails
    • Other (please specify):

Does this bug occur in a fresh installation?

Yes

Is this bug new? If it is a regression, in which version of the browser did this bug first appear?

Sometime after 140

Does this bug occur in the Alpha release channel?

Yes