"Start video call" button in card should link to talk.brave.com/widget

[stephendonner]

Description

Start video call button in card should link to talk.brave.com/widget

Steps to Reproduce

1. new profile
2. launch Brave
3. load a new-tab page
4. click on Edit cards
5. add the Brave Together (to be renamed to Brave Talk) card
6. open the Network panel in Developer Tools
7. click on the Start video call button
8. look at the URLs/redirects

Actual result:

button	URL

Expected result:

Should go to talk.brave.com/widget without any loads to/redirects from together.brave.com

Reproduces how often:

100%

Brave version (brave://version info)

Brave	1.29.20 Chromium: 92.0.4515.107 (Official Build) nightly (x86_64)
Revision	87a818b10553a07434ea9e2b6dccf3cbe7895134-refs/branch-heads/4515@{#1634}
OS	macOS Version 12.0 (Build 21A5284e)

cc @mattmcalister @rebron @bsclifton

[stephendonner]

@bsclifton think we can get an uplift going for 1.28.x? /cc @mattmcalister

[bsclifton]

@stephendonner done - brave/brave-core#9608

[kjozwiak]

Adding QA/Blocked until we get Brave Talk enabled on main (staging) via Griffin. After it's enabled on staging, QA will be able to run through the above verification. Once we get closer to Brave Talk release date, we'll push the same change into production.

[kjozwiak]

Removing QA/Blocked as brave/brave-variations#93 was merged into main (Griffin staging).

[GeetaSarvadnya]

Verification passed on

Brave | 1.28.105 Chromium: 92.0.4515.131 (Official Build) (64-bit)
-- | --
Revision | 6b8d6c56ce21e38a72f7c4becb5abc1fa5134f29-refs/branch-heads/4515@{#1933}
OS | Windows 10 OS Version 2009 (Build 19043.1110)

• Verified the STR from the description, additional testing is covered in "Try it out" should link to talk.brave.com/widget on promo tooltip #17147 (comment)
• Confirmed click on Start video call in NTP widgets redirects to https://talk.brave.com/widget
• Confirmed click on Start video call in https://talk.brave.com/widget initiates the call successfully