Stop using custom user agent, work towards generic one

[Kevin]

Ubuntu's Chromium build uses a custom user agent in many ways. It included "Ubuntu" in the .deb versions, and now it includes "snap" in the snap versions. Also, it adds a "Chromium/<version>" field. This breaks many websites that do aggressive user agent matching, such as Netflix and Microsoft Teams.

(Yes, unfortunately I have to use the latter every now and then, and I do not want to install the proprietary blob app for it.)

Chromium snap's current user agent is "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) snap Chromium/81.0.4044.129 Chrome/81.0.4044.129 Safari/537.36"

While normal Chrome's current user agent is "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/81.0.4044.129 Safari/537.36"

Pretty much every incompatibility-related issue is solved by spoofing the user agent and removing the "snap Chromium/81.0.4044.129" part, simply claiming to be normal Chrome. There is not really any point in differentiating between Chromium and Chrome, but it breaks many websites, and it's also a nasty feature for browser fingerprinting.

Identifying as Chromium will only annoy users and have them install the proprietary Chrome browser instead, so "Netflix works" and "they can join their meeting".

In order to work around such issues, Vivaldi has already decided to just use Chrome's user agent, because otherwise things broke for no obvious reasons:

https://vivaldi.com/blog/user-agent-changes/

Moreover, Google has decided to semi-deprecate user agents altogether in upcoming Chrome releases:

https://www.zdnet.com/article/google-to-phase-out-user-agent-strings-in-chrome/
https://9to5google.com/2020/01/14/google-deprecate-chrome-user-agent-string-privacy/

So with these upcoming changes in Chrome, can Chromium in Ubuntu please follow suit, and no longer differentiate from whatever string Google will use for Chrome?

$ lsb_release -rd
Description: Ubuntu 20.04 LTS
Release: 20.04

$ snap info chromium
name: chromium
summary: Chromium web browser, open-source version of Chrome
publisher: Canonical*
store-url: https://snapcraft.io/chromium
contact: https://bugs.launchpad.net/ubuntu/+source/chromium-browser/+bugs?field.tag=snap
license: unset
description: |
  An open-source browser project that aims to build a safer, faster, and more stable way for all
  Internet users to experience the web.
commands:
  - chromium.chromedriver
  - chromium
snap-id: XKEcBqPM06H1Z7zGOdG5fbICuf8NWK5R
tracking: latest/stable
refresh-date: 6 days ago, at 10:41 CEST
channels:
  latest/stable: 81.0.4044.129 2020-04-29 (1135) 161MB -
  latest/candidate: 81.0.4044.129 2020-04-28 (1135) 161MB -
  latest/beta: 83.0.4103.23 2020-04-25 (1125) 163MB -
  latest/edge: 84.0.4128.3 2020-04-29 (1136) 164MB -
installed: 81.0.4044.129 (1135) 161MB -

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.