[iOS] Enable New Playlist UI to Beta and Nightly [staging]

[iccub]

Fixes #1148

[github-actions]

✅ Test Seed Generated Successfully

To apply the test seed:

1. Desktop: Launch the browser with --variations-pr=1149.
   Android: Set the command line to --variations-pr=1149 in debug menu, restart the browser.
   iOS: Set Variations PR to 1149 in Brave Core Switches debug menu, restart the browser.
2. Wait 5-10 seconds to fetch the seed.
3. Restart the browser to apply the seed.
4. Ensure Active Variations section at brave://version starts with the expected seed version (see below).

Seed Details

• Version: pull/1149@f702a04701b08f8681bc74d7b72f8e7746732c11
• Uploaded: 2024-08-01T16:45:39.268Z
• Serial Number: bc26d60f7af322543e38bc5c4215f8b5

[kjozwiak]

The following basically ensures that the new Playlist UI/UX is being displayed/used on only Nightly & BETA. The feature will be verified in more detail once QA starts running through the feature.

Nightly verification(s)

Verification PASSED on iPhone 11 running iOS 17.5.1 using the following build(s):

Brave | 1.70.41 Chromium: 127.0.6533.88 (Official Build) nightly (64-bit) 
--- | ---
Revision | 9303bae9fe07...
OS | iOS

Using the STR/Cases outlined via #1149 (comment), ensured that the new Playlist feature is being enabled on Nightly without any issues.

• ensured that pull/1149@f702a04701b08f8681bc74d7b72f8e7746732c11 is being displayed via brave://version
• verified that the new Playlist onboarding is being displayed/shown via Hamburger Menu -> Playlist
• ensured that the new UI/UX is being displayed when viewing a video that has already been saved

Example	Example	Example	Example	Example

---

BETA verification(s)

Verification PASSED on iPhone 11 running iOS 17.5.1 using the following build(s):

Brave | 1.69.131 Chromium: 127.0.6533.88 (Official Build) beta (64-bit)
--- | ---
Revision | 7f9c5cb9840e...
OS | iOS

Using the STR/Cases outlined via #1149 (comment), ensured that the new Playlist feature is being enabled on Nightly without any issues.

• ensured that pull/1149@f702a04701b08f8681bc74d7b72f8e7746732c11 is being displayed via brave://version
• verified that the new Playlist onboarding is being displayed/shown via Hamburger Menu -> Playlist
• ensured that the new UI/UX is being displayed when viewing a video that has already been saved

Example	Example	Example	Example	Example

---

Release verification(s)

Verification PASSED on iPhone 11 running iOS 17.5.1 using the following build(s):

Brave | 1.68.134 Chromium: 127.0.6533.88 (Official Build) stable (64-bit) 
--- | ---
Revision | 71f3c9cc80f9...
OS | iOS

Using the STR/Cases outlined via #1149 (comment), ensured that the new Playlist feature is being enabled on Nightly without any issues.

• ensured that pull/1149@f702a04701b08f8681bc74d7b72f8e7746732c11 is being displayed via brave://version
• ensured that the new Playlist UI/UX is NOT being applied to Release as per https://github.com/brave/brave-variations/pull/1149/files#diff-7ac2945ede68c73330363911678f6c9a2a6290b70e2dd170868295f65da7e872R3045

Example	Example	Example	Example

[kjozwiak]

LGTM 👍 Merging into master so we can uplift/merge #1150 into production.