Miss USB device Interface from UsbManager.getDeviceList().

In the scenario that you connect more than one device to android phone with an usb hub,
when you attach the second device,mNewConfigurationis is still corresponded to the first
device unless another mNewConfiguration is created by a new operation.
However,before another mNewConfiguration is created,setInterfaces() in addUsbConfiguration()
has already been executed. Problem is that mNewInterfaces has already been cleared when
it finished endUsbDeviceAdded for the first device. As a result,the UsbInterface descriptor
in the first device's Configuration descriptor is set to null.

Change-Id: I0ba4f07c809d07ebebed633e43c3ee8e2e4c5060