Cookie List should be enabled at first launch

[rebron]

Description

Set Cookie List filter (Easylist - Cookie List) as enabled for all new and existing users.

See: #10433

Expected result:

1. Start browser with a new profile.
2. Navigate to brave://adblock.
3. Expand the list of filters, and verify that the "Cookie List" filter has been enabled.

Brave version (brave://version info)

tbd.

Version/Channel Information:

• Can you reproduce this issue with the current release? n/a
• Can you reproduce this issue with the beta channel? n/a
• Can you reproduce this issue with the nightly channel? n/a

Other Additional Information:

• Does the issue resolve itself when disabling Brave Shields? n/a
• Does the issue resolve itself when disabling Brave Rewards? n/a
• Is the issue reproducible on the latest version of Chrome? n/a

Miscellaneous Information:

Related issue: #10433

[arthuredelstein]

One idea could be to show an in-app notification to users informing them that blocking has been turned on by default. This would:

• Let users know about a very nice built-in feature in Brave.
• Ensure that any users who have previously said "no" to cookie prompt blocking are aware that blocking will now be happening (and giving them a link to turn off blocking again if they really wish to do so).

[antonok-edm]

@rebron I updated the issue slightly - the dialog code will be repurposed according to https://bravesoftware.slack.com/archives/C06UXF3KJ/p1692219055340939?thread_ts=1692213061.694329&cid=C06UXF3KJ, and it's already off by default in the code, so no changes required there. Just going to turn the Griffin flag ON by default for enabling the cookie list.

[kjozwiak]

The above requires 1.58.117 or higher for 1.58.x verification 👍

[LaurenWags]

Verified with

Brave | 1.58.117 Chromium: 116.0.5845.180 (Official Build) (x86_64)
-- | --
Revision | 99255ad6abf2fa399c063683c051f973e1f5c0af
OS | macOS Version 13.5.2 (Build 22G91)

Using the STR/Cases outlined via #29986 (comment), went through the following and ensured that brave://flags#brave-adblock-cookie-list-default enabled is being enabled by default on first launch.

• ensured that the Default for brave://flags#brave-adblock-cookie-list-default enabled is set as Enabled
• ensured that EasyList Cookies is enabled via brave://settings/shields/filters on first launch
• ensured that there's no cookie consent message appearing under https://www.digikey.com on first launch
• ensured that brave://flags#brave-adblock-cookie-list-default enabled is still enabled after restarting the browser
  • basically ensuring that once Griffin studies are being applied, #brave-adblock-cookie-list-default enabled is still enabled
  • ensured that EasyList Cookies is still enabled via brave://settings/shields/filters once Griffin studies are applied
• ensured that the cookie consent banner is appearing under https://www.digikey.com after disabling EasyList Cookies
  • disabled via brave://settings/shields/filters and ensured disabling/enabling worked as expected

Before Restarting (no Griffin studies applied)

Example	Example	Example	Example

After Restarting (Griffin studies being applied)

Example	Example

After disabling EasyList Cookies via brave://settings/shields/filters