Change UsbManager.requestPermission to only grant permission temporarily

If the user approves an application to access a USB device or accessory
without choosing it as the default application, then permission is granted
only until the device or accessory is disconnected.
Only applications chosen as the default choice have permissions assigned persistently.

BUG: 4061035

Change-Id: Ic4f6271a91b2fc56bbeef82c579e26d88c63ae56
Signed-off-by: Mike Lockwood <lockwood@android.com>