Android: Try to parse the QML port from stderr

Most of the time the port is not announced on stdout but on stderr.

Change-Id: If72bb7f65dcfe7e697de2545d33e99ddb6363ecf
Reviewed-by: Daniel Teske <daniel.teske@digia.com>
Reviewed-by: Kai Koehne <kai.koehne@digia.com>