fix: make saving state logs to a file on Android more performant

[joaoloureirop]

Description

On Android, Settings → Advanced → Download State Logs was slow to respond, and when the share window finally appeared it only offered "send to" targets (email/messaging/apps) with no way to actually save or download the logs file.

The cause was that Android shared the logs as a base64 data:text/plain URL via Share.open. Encoding the entire state to base64 was slow for large states, and the result was a text-only share intent with no file to save.

This PR makes state logs a real file download on both platforms:

• The logs are written to a file (as iOS already did) and shared by their plain path with a filename and application/json MIME type. react-native-share copies the file into its own FileProvider and shares a content:// URI, so Android's share sheet now offers "Save to Files"/Drive. (A raw file:// URI is intentionally avoided — it would crash Android with FileUriExposedException.)
• Dropping the base64 encoding step also removes the delay that prompted the report.

iOS behavior is unchanged in practice (it already wrote and shared the file); the share path is now unified across platforms.

Changelog

CHANGELOG entry: Fixed Download State Logs on Android so the logs can be saved/downloaded as a file, and removed the delay before the share sheet appears

Related issues

Fixes: #24359

Manual testing steps

Feature: Download state logs on Android

  Scenario: User downloads and saves state logs
    Given I am on an Android device with the wallet unlocked
    And I navigate to Settings > Advanced

    When I tap "Download state logs"
    Then the share sheet appears promptly
    And it offers an option to save/download the file (e.g. "Save to Files"/Drive)

  Scenario: User saves the file
    Given the share sheet is open
    When I choose "Save to Files" (or Drive) and confirm
    Then a "state-logs-v<version>-(<build>).json" file is saved and can be reopened

Screenshots/Recordings

Before

Not applicable

After

Not applicable

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.

Performance checks (if applicable)

• I've tested on Android
  • Ideally on a mid-range device; emulator is acceptable
• I've tested with a power user scenario
  • Use these power-user SRPs to import wallets with many accounts and tokens
• I've instrumented key operations with Sentry traces for production performance metrics
  • See trace() for usage and addToken for an example

For performance guidelines and tooling, see the Performance Guide.

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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[github-actions]

🔍 Smart E2E Test Selection

• Selected E2E tags: None (no tests recommended)
• Selected Performance tags: None (no tests recommended)
• Risk Level: low
• AI Confidence: 97%

click to see 🤖 AI reasoning details

E2E Test Selection:
The PR modifies only two files: app/util/logs/index.ts and its test file app/util/logs/index.test.ts. The changes refactor the downloadStateLogs utility function to write state logs to a real file on both iOS and Android (previously Android used a base64 data URL), and share the file path instead. Additional share options (filename, type: 'application/json', failOnCancel: false) are added. The Buffer and Device imports are removed as they are no longer needed. This is a diagnostic/developer utility triggered only by a long-press on the Login screen — it is not part of any core wallet flow (accounts, transactions, networks, swaps, etc.). No E2E tests cover this specific feature. The changes are fully covered by updated unit tests. No shared components (navigation, modals, confirmations, controllers) are affected. Zero E2E tags are warranted.

Performance Test Selection:
The changes are limited to the state logs download utility function. This is a diagnostic feature triggered by a long-press gesture on the login screen and has no impact on any performance-measured flows (app launch, login, onboarding, swaps, asset loading, account list, etc.). No performance tests are warranted.

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