fix: cp-7.46.0 show "auto" when slippage is undefined

[bfullam]

Description

Shows "Auto" as the slippage text on Solana swaps when the slippage is undefined. This case is for LiFi so it uses their dynamic slippage.

Related issues

Fixes:

Manual testing steps

1. Go to this solana swap
2. Get quotes
3. See "Auto" as slippage value

Screenshots/Recordings

Before

After

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• 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]

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[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
66.7% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud