Filter out devices that do not support any format supported by WebRTC.
This will for example be IR cameras that show as duplicated in the list
of cameras, but support only GRAY8 format and for that reason do not
work at all.
This is a simple backport of an WebRTC upstream change.
Upstream commit: b4aba7834e6c94adace1cb4c20e2e1ee70eb9cc5