Fix QBluetoothSocket::isReadable()/isOpen()/isWritable()

Change-Id: Ifd6b5ed8176aa7959ed8da0edc762266aa2bd6fa
Task-number: QTBUG-32704
Reviewed-by: Timur Pocheptsov <Timur.Pocheptsov@digia.com>
Reviewed-by: Alex Blasche <alexander.blasche@digia.com>
Fix QBluetoothSocket unit test failures on Android

Change-Id: Ib8800fa30c74678c74df9ed943b143ea4cf49bb2
Reviewed-by: Timur Pocheptsov <Timur.Pocheptsov@digia.com>
Reviewed-by: Alex Blasche <alexander.blasche@digia.com>