Retain remoteusermedia modifications across sessions

[Half-Shot]

Fixes #3594

This adds a new settings type that is per-userId, that tracks settings you've applied to another user and retains them for the next call.

TODO: Need to think about per-userId+deviceId, as you probably only want this to apply to the specific device the user is using (at least for media controls)

[fkwp]

@daniellekirkwood I think this need Product Input