Always defaulting to offerToReceiveAudio and offerToReceiveVideo true values for a createOffer is not correct

[DamonOehlman]

While this is a helpful "feature" that was added to make it easier for people to make "listen" only connections using quickconnect, it has some undesirable side effects:

1. When you might be expecting that only an audio stream is being communicated (in the case that you have supplied an audio only stream) video is still being communicated.
2. When working with a data only connection, a fake media stream is also being added.

This should be reset to not assume any particular createOffer constraints.