UsbDevice: Move IO related methods to new UsbDeviceConnection class

UsbDevice is now just an immutable parcelable object like UsbInterface and
UsbEndpoint.
All IO related functionality is now contained in UsbDeviceConnection
and UsbRequest.

Bug: 4067029

Change-Id: Ia84da0b512a697acc940eee0c3566711c62e1a68
Signed-off-by: Mike Lockwood <lockwood@android.com>
14 files changed