You can find the android.hardware.usb.host.xml file in the Android Open Source Project (AOSP) repository. Specifically, you can find it in the following location:
https://source.android.com/devices/tech/connect/xsd androidhardwareusbhostxml file download 2021
The android.hardware.usb.host.xml file is part of the Android 11 (R) release, which was released in 2021. You can find the file for Android 11 (R) in the AOSP repository. You can find the android
https://android.googlesource.com/platform/frameworks/base/+/master/data/etc/permissions androidhardwareusbhostxml file download 2021