No meaningful error message when user media gets denied

[rantonysamy]

Description
We should have a meaningful error message to the user when user media request denied by the user.

as of now the page responds as "User media request denied with error code undefined"

Steps

Open a fresh tab and go to webrtc.github.io/test-pages/src/single-video
Respond as "Deny" to the authorization Info bubble
Refresh the Page

Expected Result
Meaningful error message to the user, that the authentication has been blocked

Actual Result
Message "User media request denied with error code undefined" shows up as a pop-up.

Reference
Screenshot attached.