Build, sign and publish Beta 4 (1.4.0Beta) to the Play Store

Beta 4 is due to be published to the Play Store week commencing December 8th.

Changelog (to be written by @donuts):

Beta 4 (1.4.0Beta) adds support WebTunnel bridges to Tor VPN. This release also features an update to onionmasq, fixes several bugs and crashes, and includes other minor improvements.

For the full changelog, please see here:
https://gitlab.torproject.org/tpo/applications/vpn/-/blob/main/CHANGELOG.md

Todo list:

• Tag onionmasq
• Update deps in vpn
• Update onionmasq.hash in vpn
• Update built-in bridges
• Update translation.hash in vpn
• Probably run and include python3 scripts/get-l10n.py
  • Do not include cs and sk as they are not ready and have errors as of last check
• Tag vpn

Note: I copy-pasted the todo list from Beta 3's publication, however maybe it's not all relevant to this release – please feel free to modify as you see fit.