Support multi function USB hubs

Some "modern" USB hubs, especially the Type-C ones which are also used by Macbooks, can contain multiple functions, such as HDMI output, SD card reader, Ethernet port, etc.

The one USB hub I have (Verbatim 7-in-1 hub, model number VAPCH047), when listing devices with UsbManager.getDeviceList(), will have such output. This is the case of plugging in both an USB thumbdrive and SD card onto the hub.

result = {HashMap@14377}  size = 2
 "/dev/bus/usb/001/004" -> {UsbDevice@14383} "UsbDevice[mName=/dev/bus/usb/001/004,mVendorId=1423,mProductId=25479,mClass=0,mSubclass=0,mProtocol=0,mManufacturerName=Generic,mProductName=Mass Storage,mVersion=1.03,mSerialNumber=993207CA,mConfigurations=[\nUsbConfiguration[mId=1,mName=null,mAttributes=128,mMaxPower=50,mInterfaces=[\nUsbInterface[mId=0,mAlternateSetting=0,mName=null,mClass=8,mSubclass=6,mProtocol=80,mEndpoints=[\nUsbEndpoint[mAddress=1,mAttributes=2,mMaxPacketSize=512,mInterval=0]\nUsbEndpoint[mAddress=130,mAttributes=2,mMaxPacketSize=512,mInterval=0]]]]"
  key = "/dev/bus/usb/001/004"
  value = {UsbDevice@14383} "UsbDevice[mName=/dev/bus/usb/001/004,mVendorId=1423,mProductId=25479,mClass=0,mSubclass=0,mProtocol=0,mManufacturerName=Generic,mProductName=Mass Storage,mVersion=1.03,mSerialNumber=993207CA,mConfigurations=[\nUsbConfiguration[mId=1,mName=null,mAttributes=128,mMaxPower=50,mInterfaces=[\nUsbInterface[mId=0,mAlternateSetting=0,mName=null,mClass=8,mSubclass=6,mProtocol=80,mEndpoints=[\nUsbEndpoint[mAddress=1,mAttributes=2,mMaxPacketSize=512,mInterval=0]\nUsbEndpoint[mAddress=130,mAttributes=2,mMaxPacketSize=512,mInterval=0]]]]"
   mClass = 0
   mConfigurations = {Parcelable[1]@14413} 
   mInterfaces = null
   mManufacturerName = "Generic"
   mName = "/dev/bus/usb/001/004"
   mProductId = 25479
   mProductName = "Mass Storage"
   mProtocol = 0
   mSerialNumber = "993207CA"
   mSubclass = 0
   mVendorId = 1423
   mVersion = "1.03"
   shadow$_klass_ = {Class@1323} "class android.hardware.usb.UsbDevice"
   shadow$_monitor_ = 0
 "/dev/bus/usb/001/003" -> {UsbDevice@14385} "UsbDevice[mName=/dev/bus/usb/001/003,mVendorId=1507,mProductId=1865,mClass=0,mSubclass=0,mProtocol=0,mManufacturerName=Generic,mProductName=USB3.0 Card Reader,mVersion=15.39,mSerialNumber=000000001539,mConfigurations=[\nUsbConfiguration[mId=1,mName=null,mAttributes=128,mMaxPower=250,mInterfaces=[\nUsbInterface[mId=0,mAlternateSetting=0,mName=null,mClass=8,mSubclass=6,mProtocol=80,mEndpoints=[\nUsbEndpoint[mAddress=129,mAttributes=2,mMaxPacketSize=512,mInterval=0]\nUsbEndpoint[mAddress=2,mAttributes=2,mMaxPacketSize=512,mInterval=0]]]]"
  key = "/dev/bus/usb/001/003"
  value = {UsbDevice@14385} "UsbDevice[mName=/dev/bus/usb/001/003,mVendorId=1507,mProductId=1865,mClass=0,mSubclass=0,mProtocol=0,mManufacturerName=Generic,mProductName=USB3.0 Card Reader,mVersion=15.39,mSerialNumber=000000001539,mConfigurations=[\nUsbConfiguration[mId=1,mName=null,mAttributes=128,mMaxPower=250,mInterfaces=[\nUsbInterface[mId=0,mAlternateSetting=0,mName=null,mClass=8,mSubclass=6,mProtocol=80,mEndpoints=[\nUsbEndpoint[mAddress=129,mAttributes=2,mMaxPacketSize=512,mInterval=0]\nUsbEndpoint[mAddress=2,mAttributes=2,mMaxPacketSize=512,mInterval=0]]]]"
   mClass = 0
   mConfigurations = {Parcelable[1]@14404} 
   mInterfaces = null
   mManufacturerName = "Generic"
   mName = "/dev/bus/usb/001/003"
   mProductId = 1865
   mProductName = "USB3.0 Card Reader"
   mProtocol = 0
   mSerialNumber = "000000001539"
   mSubclass = 0
   mVendorId = 1507
   mVersion = "15.39"
   shadow$_klass_ = {Class@1323} "class android.hardware.usb.UsbDevice"
   shadow$_monitor_ = 0

Both devices have device class = 0 (UsbConstants.USB_CLASS_PER_INTERFACE), contrary to OTGUtil's requirement of 8 (UsbConstants.USB_CLASS_MASS_STORAGE).

https://github.com/TeamAmaze/AmazeFileManager/blob/022e3b299f7bf7557930a5019153ea658ad48301/app/src/main/java/com/amaze/filemanager/utils/OTGUtil.kt#L157-L187

We should be able to support such situations. Additionally, we should be able to support multiple OTG storage plugged into the USB hub as well. This implies changing OTG's implementation to make OTG paths like otg://<storage volume> instead of just otg://.

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Start with app/src/main/java/com/amaze/filemanager/utils/OTGUtil.kt, especially lines 157-187, and trace how OTG paths are created and resolved. Check the USB device handling around the reported USB_CLASS_PER_INTERFACE case; done means multi-function hubs and multiple OTG storage devices can be listed and addressed through distinct otg:// paths.