Support for multiple USB OTG + option to enable direct access to USB OTG

[TranceLove]

Description

Enable multiple USB OTG plugged into device via USB hub.

With this changeset, it is possible to navigate across different USB storage plugged into the device via USB OTG.

Aside, where VolumeManager access to USB storage is possible, added an option to enable direct access to USB storage via filesystem (java.io) APIs instead of Android's own Storage Access Framework.

However, it does has a caveat: OTG I/O are synchronized while direct filesystem access is not. If you unplug the device without letting system to sync, files may or may not be gone. You have the responsibility to gracefully eject the device via pulldown or DocumentsUI. Therefore this option is off by default.

Issue tracker

Fixes #2633, #1256

Automatic tests

• Added unit tests for specific individual functions
• Added headless tests for new app functionality
• Added emulator tests for new UI elements

Manual tests

• Done

• Device:

• OS:

Build tasks success

Successfully running following tasks on local:

• ./gradlew assembledebug
• ./gradlew spotlessCheck

Generative code

• This PR used generative code tools (GenAI, LLMs, etc.)

This implementation is completed with Copilot's help.

• Model: Claude
• Version: Sonnet 4.6
• Provider: Github Copilot

[TranceLove]

User Acceptance Test

Operation	Tested with OTG	Tested with native filesystem access
Browse USB storage
Create file on USB storage root
Create file on USB storage subfolder
Create folder on USB storage root
Create folder on USB storage subfolder
Copy file from device to USB storage
Copy file from USB storage to device
Copy file from between USB storage devices
Move file from between USB storage devices
Move file from device to USB storage
Move file from USB storage to device
Delete folder from USB storage
Delete file from USB storage
Eject USB storage when native filesystem access is enabled	N/A