Brave Together => Brave Talk changes - (uplift to 1.28.x)

[brave-builds]

Uplift of #9468
Fixes brave/brave-browser#16799

Uplift of #9581
Fixes brave/brave-browser#17146
Fixes brave/brave-browser#17147

Uplift of #9552
Fixes brave/brave-browser#16798

Uplift of #9605
Fixes brave/brave-browser#17138
Fixes brave/brave-browser#17210

Pre-approval checklist:

• You have tested your change on Nightly.
• This contains text which needs to be translated.
  • There are more than 7 days before the release.
  • I've notified folks in #l10n on Slack that translations are needed.
• The PR milestones match the branch they are landing to.

Pre-merge checklist:

• You have checked CI and the builds, lint, and tests all pass or are not related to your PR.

Post-merge checklist:

• The associated issue milestone is set to the smallest version that the changes is landed on.

[kjozwiak]

With 1.29.47 or higher, Brave Talk will be disabled by default and will need to be enabled via Griffin. QA won't be able to QA/Verify brave/brave-browser#17210 until we push the change to Griffin and enable Brave Talk on Nightly at 100% or users will notice that Brave Talk has been removed.

Once the Griffin change is live, QA will be able to run through brave/brave-browser#17210. CCing @stephendonner

[kjozwiak]

Uplift into 1.28.x approved after deliberating with @brave/uplift-approvers. QA has verified the PR on Nightly as per brave/brave-browser#16799 (comment), #9581 (comment), brave/brave-browser#16798 (comment) & #9605 (comment). @stephendonner also checked both main (staging) & production (release).