DO NOT MERGE Tethering: Delay 1000ms before processing USB disconnect events

This change is already in master

On some devices, switching the USB configuration to enable RNDIS can
result in multiple USB disconnect/reconnect events being generated.

Change-Id: I14b02aaca11bb708f6b3334e41a2f4d4fa7b7296
Signed-off-by: Mike Lockwood <lockwood@android.com>