Add Group policy for playlist

[kdenhartog]

Platforms

Linux, macOS, Windows

Description

In brave/brave-core#25710 we started to migrate towards group policies that match how Chromium does it. We currently have a few group policies for Brave specific features and this issue is to add a new policy that would disable playlist as well.

[bsclifton]

Folks who were interested in this - you can check out the steps outlined here:
https://github.com/brave/brave-core/tree/master/components/policy/resources/templates/policy_definitions

Those go over the steps needed to create a new policy. You can also search our pull requests for group policy to find some of the prior implementations folks have done.

[deepthiteki]

Please assign this to me

[bregwin]

Hi! If this feature hasn't been completed, can I work on it? I don't need to be assigned to it.

[kdenhartog]

Certainly, I've not seen a PR for it yet so this is still free for anyone to work on.