In BBB ≤ 2.7, a procedure monitored system audio device changes, updating
the device list and assigning a fallback device if the current one was removed.
This procedure was removed in 3.0 during the migration of the
input-stream-live-selector component to TypeScript (reasons unknown), causing
the device list to become outdated and leaving the user's client without audio
input if their current device is disconnected.
This commit restores the `devicechange` event handler in the input-stream-live-
selector, ensuring that the device list is updated properly and fallback devices
are assigned when necessary.
7dd0fb42ea