You don't usually "download" this file separately—it's part of the Android source code. But if you need a copy:
In 2021, Project Treble became mainstream, allowing users to install Generic System Images on unsupported devices. Many GSIs lacked device-specific configuration files, including the USB host permission file. androidhardwareusbhostxml file download 2021
For legacy or rooted Android 10/11 devices: Project Treble became mainstream
If you see feature:android.hardware.usb.host , the installation was successful. androidhardwareusbhostxml file download 2021
To enable this feature, the file must contain the following permission declaration: