Impending consensus: always allow persisting deviceIds (Issue #322)

All,

there has been a discussion in #322 [1] to remove the part that says
that persisting deviceIds between browsing sessions is conditioned on
the user granting access (or that there is a persistent permission) to 
use a microphone or camera for the origin.

The discussion in [1] concludes that we can remove this condition
without any privacy ill effects, and PR #326 [2] implements this in the
spec.

Everyone discussing in the Issue [1] seems to be in favor of making this 
change.

If nobody speaks up against it, we'll take that as TF consensus and go
on to make the change.


[1] https://github.com/w3c/mediacapture-main/issues/322
[2] https://github.com/w3c/mediacapture-main/pull/326