chore: removing duplicate icons and updating account splash page

[georgewrmarshall]

Description

This PR removes design and tech debt by cleaning up unused icon assets and modernizing the SmartAccountUpdateSplash component implementation.

What is the reason for the change?

• The previous implementation in PR feat: Adding splash page to upgrade account request #15355 added new filled icon variants (SpeedometerFilled, SparkleFilled, PetrolPump) when existing icons could be used
• The component was using the older Icon component instead of the modern AvatarIcon component
• Unused SVG assets were taking up space in the codebase

What is the improvement/solution?

• Removed 3 unused SVG files and their corresponding imports/enum entries
• Replaced Icon component with AvatarIcon component for better design consistency
• Updated icon names to use existing variants: SpeedometerFilled → Speedometer, PetrolPump → Gas, SparkleFilled → Sparkle
• Added proper theming support with useTheme hook
• Improved component structure by converting ListItem from arrow function to proper function component

Related issues

Fixes: N/A

Manual testing steps

1. Navigate to a confirmation flow that triggers the Smart Account Update Splash
2. Verify that all three list items display with correct icons (speedometer, gas pump, sparkle)
3. Confirm that icons use proper theming (primary color with muted background)
4. Test in both light and dark themes to ensure proper color application
5. Verify that icon functionality and accessibility remain unchanged

Screenshots/Recordings

Before

• Used filled icon variants (SpeedometerFilled, SparkleFilled, PetrolPump)
• Used basic Icon component without proper theming
• Extra SVG files in codebase

After

• Uses standard icon variants (Speedometer, Gas, Sparkle)
• Uses modern AvatarIcon component with proper theming
• Cleaner codebase with removed unused assets

Pre-merge author checklist

• I've followed MetaMask Contributor Docs and MetaMask Mobile Coding Standards.
• I've completed the PR template to the best of my ability
• I've included tests if applicable
• I've documented my code using JSDoc format if applicable
• I've applied the right labels on the PR (see labeling guidelines). Not required for external contributors.

Pre-merge reviewer checklist

• I've manually tested the PR (e.g. pull and build branch, run the app, test code being changed).
• I confirm that this PR addresses all acceptance criteria described in the ticket it closes and includes the necessary testing evidence such as recordings and or screenshots.

[github-actions]

CLA Signature Action: All authors have signed the CLA. You may need to manually re-run the blocking PR check if it doesn't pass in a few minutes.

[github-actions]

Bitrise

❌❌❌ pr_smoke_e2e_pipeline failed on Bitrise! ❌❌❌

Commit hash: b6edbd6
Build link: https://app.bitrise.io/app/be69d4368ee7e86d/pipelines/60967fe6-7748-4170-81c5-21f115e55894

Note

• You can kick off another pr_smoke_e2e_pipeline on Bitrise by removing and re-applying the Run Smoke E2E label on the pull request

Tip

• Check the documentation if you have any doubts on how to understand the failure on bitrise

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
100.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[brianacnguyen]

Thank you