BluetoothDialog view fixed for no pair code case

BluetoothPairingDialog no longer asks for a
pair code when the user only needs to
confirm that they would like to connect
to a device. Also, the layout padding
was updated a bit to make it look nicer.

Test: RunSettingsRoboTests
Bug: 31340598
Change-Id: I9394fcd53dffcff9a17fbafabdce0e94ae88fba2