StreamedMediaChannel::onStreamAdded: fix defaults for stream direction
StreamedMediaChannel::onStreamAdded: fix defaults for stream direction

From the spec:

... clients SHOULD assume that the initial Media_Stream_Direction of a newly added stream is
Receive, and that the initial Media_Stream_Pending_Send is Pending_Local_Send. ...

Reviewed-by: Andre Magalhaes (andrunko) <ab0884a012ded4e51536cd4c0ccf5fa57e1a637b@collabora.co.uk>

tiagosh/telepathy-qt,TelepathyIM/telepathy-qt,TelepathyIM/telepathy-qt,detrout/telepathy-qt,freedesktop-unofficial-mirror/telepathy__telepathy-qt4,detrout/telepathy-qt,freedesktop-unofficial-mirror/telepathy__telepathy-qt,freedesktop-unofficial-mirror/telepathy__telepathy-qt4,freedesktop-unofficial-mirror/telepathy__telepathy-qt,freedesktop-unofficial-mirror/telepathy__telepathy-qt4,tiagosh/telepathy-qt,anantkamath/telepathy-qt,freedesktop-unofficial-mirror/telepathy__telepathy-qt,special/telepathy-qt-upstream,TelepathyIM/telepathy-qt,detrout/telepathy-qt,anantkamath/telepathy-qt,freedesktop-unofficial-mirror/telepathy__telepathy-qt4,tiagosh/telepathy-qt,TelepathyIM/telepathy-qt,TelepathyQt/telepathy-qt,TelepathyIM/telepathy-qt,TelepathyQt/telepathy-qt,special/telepathy-qt-upstream,special/telepathy-qt-upstream,anantkamath/telepathy-qt,TelepathyQt/telepathy-qt,TelepathyQt/telepathy-qt,freedesktop-unofficial-mirror/telepathy__telepathy-qt,tiagosh/telepathy-qt