[iOS] Add dark & tinted mode icons for iOS 18

[kylehickinson]

This change also updates the app icons to use a single size and let Xcode/iOS generate the required sizes since the icon itself is just scaled at the design side

Resolves brave/brave-browser#41088

Submitter Checklist:

• I confirm that no security/privacy review is needed and no other type of reviews are needed, or that I have requested them
• There is a ticket for my issue
• Used Github auto-closing keywords in the PR description above
• Wrote a good PR/commit description
• Squashed any review feedback or "fixup" commits before merge, so that history is a record of what happened in the repo, not your PR
• Added appropriate labels (QA/Yes or QA/No; release-notes/include or release-notes/exclude; OS/...) to the associated issue
• Checked the PR locally:
  • npm run test -- brave_browser_tests, npm run test -- brave_unit_tests wiki
  • npm run presubmit wiki, npm run gn_check, npm run tslint
• Ran git rebase master (if needed)

Reviewer Checklist:

• A security review is not needed, or a link to one is included in the PR description
• New files have MPL-2.0 license header
• Adequate test coverage exists to prevent regressions
• Major classes, functions and non-trivial code blocks are well-commented
• Changes in component dependencies are properly reflected in gn
• Code follows the style guide
• Test plan is specified in PR before merging

After-merge Checklist:

• The associated issue milestone is set to the smallest version that the
  changes has landed on
• All relevant documentation has been updated, for instance:
  • https://github.com/brave/brave-browser/wiki/Deviations-from-Chromium-(features-we-disable-or-remove)
  • https://github.com/brave/brave-browser/wiki/Proxy-redirected-URLs
  • https://github.com/brave/brave-browser/wiki/Fingerprinting-Protections
  • https://github.com/brave/brave-browser/wiki/Brave%E2%80%99s-Use-of-Referral-Codes
  • https://github.com/brave/brave-browser/wiki/Web-Compatibility-Exceptions-in-Brave
  • https://github.com/brave/brave-browser/wiki/QA-Guide
  • https://github.com/brave/brave-browser/wiki/P3A

Test Plan:

On each channel (as CI makes appropriate builds):

• Test that on iOS 18 the correct icons appear based on the selected appearance mode (light, dark, tinted)
• Test that on iOS 16/17 the standard light mode app icon appears

[github-actions]

[puLL-Merge] - brave/brave-core@25603

Description

This PR updates the app icons for the iOS version of Brave Browser. It simplifies the icon set by removing multiple sizes and introduces support for different appearances (light, dark, and tinted) for each app variant (main app, Beta, Local, and Nightly).

Changes

Changes

1. ios/brave-ios/App/iOS/Icons.xcassets/AppIcon.appiconset/Contents.json

   • Removed multiple icon sizes for different devices
   • Added support for light, dark, and tinted appearances
   • Updated to use a single 1024x1024 icon for each appearance

2. ios/brave-ios/App/iOS/Icons.xcassets/AppIcon_Beta.appiconset/Contents.json

   • Similar changes as the main AppIcon, supporting light, dark, and tinted appearances

3. ios/brave-ios/App/iOS/Icons.xcassets/AppIcon_Local.appiconset/Contents.json

   • Similar changes as the main AppIcon, supporting light, dark, and tinted appearances

4. ios/brave-ios/App/iOS/Icons.xcassets/AppIcon_Nightly.appiconset/Contents.json

   • Similar changes as the main AppIcon, supporting light, dark, and tinted appearances

5. Icon files

   • Removed multiple smaller icon files for different sizes
   • Added new icon files for each appearance (light, dark, tinted) for each app variant

6. ios/brave-ios/App/iOS/Icons.xcassets/AppIcon_Dev.appiconset

   • Removed the entire AppIcon_Dev.appiconset directory and its contents

Possible Issues

1. Removal of multiple icon sizes might affect older iOS versions or devices that expect specific icon sizes. However, this is likely mitigated by iOS's ability to scale icons as needed.

2. The removal of the AppIcon_Dev.appiconset might impact development builds if they were using these icons. Ensure that this doesn't break any development workflows.

3. The new icon set relies on iOS's appearance settings (light, dark, tinted). Make sure that all supported iOS versions can handle these appearance-based icons correctly.

This PR significantly simplifies the app icon management for the iOS version of Brave Browser, which should make future icon updates easier. However, thorough testing on various iOS versions and devices is recommended to ensure compatibility and correct appearance across all scenarios.

[Uni-verse]

Verified on iPhone 12 running iOS 18 using version 1.72 (27)

iOS 18 (Home Screen)

• Verified Brave icon supports Light, Dark, Automatic and Tinted modes.
• Verified Brave icons appearing correctly when using small and large icon setting in customization panel.
• Verified using different tint configurations in Tinted mode is applied correctly.
• Verified that Brave icon shows the correct mode when using automatic mode in the home screen customize menu.
• Verified that Brave Widgets support the new Tinted mode.

light (small)	dark (small)	automatic (small)	tinted (small)
light (large)	dark (large)	automatic (large)	tinted (large)

iOS 18 Shortcuts, Dashboard + Search

• Ensured that Brave icons that appear on Home Screen dash and when searching have the correct mode applied.
• Ensured that tinted mode is applied for Shortcuts created and light/dark has not regressed for these.

example	example	example	example	example

iOS 17

• Ensured that Brave icon and widgets have not regressed for Light/Dark mode on iOS 17.x

Light	Dark

iOS 16

• Ensured that Brave icon and widgets have not regressed for Light/Dark mode on iOS 16.x

Dark	Light