Add ability to choose audio/video input device

[TheLastProject]

Description

I was trying to have a video chat with a friend who was using Riot on her macOS desktop. She could see and hear me, but I couldn't see or hear her. I assume the issue lies with Riot defaulting to an incorrect input device because she does need to choose other settings than the default settings when using Jitsi Meet. However, Riot does not seem to provide any ability to choose the input device.

Steps to reproduce

• Ensure preferred audio and/or video input device are not the default devices
• Start an audio/video call
• Observe it does not work and you cannot choose input devices

Version information

• Platform: Desktop (not browser)
• OS: macOS Sierra (10.12.2)
• Version:
  matrix-react-sdk version: 0.8.6
  vector-web version: 0.9.7
  olm version: 2.2.1

[ara4n]

dup #2822