Need something better than client's `checkForStaleness`
If no message has been received on the datachannel on the client for
SnowflakeTimeout (30 seconds),
checkForStaleness closes the connection. The comment says this is to,
// Prevent long-lived broken remotes.
but there's no heartbeat at this level of abstraction so the connection is constantly being reset anytime the user pauses their activity (for example, to read a webpage).
This greatly exacerbated #21312 (moved)