USB: Add API and dialog for apps to request permissions for USB devices and accessories

New APIs:

UsbManager.hasPermission returns true if the caller has permission
for the given device or accessory

UsbManager.requestPermission poses a dialog to allow the user to give the caller
permission for the device or accessory.
Result is returned via a PendingIntent.
No dialog is displayed if the caller already has permission.

Also moved UsbResolverActivity to SystemUI package

BUG: 4069037

Change-Id: I93be769501a8776b49ac26e468af19f8fa2114c9