DO NOT MERGE UsbManager: squashed commit of:

USB: Add functions for querying if a USB function is supported and enabled.

Rename android.hardware.Usb to UsbManager and UsbObserver to UsbService

Change-Id: I920a211934d993eab8ce744c1cc7b05342389286
Signed-off-by: Mike Lockwood <lockwood@android.com>