Make the following changes to make hedging_metrics_server_status.js more robust and testing hedge reads easier.

• Use assert.soon in checkServerStatusHedgingMetrics instead of assert.eq since the the other host might not have responded to the command request when the command finishes.
• Add a failpoint to SeverSelector that forces the replica set monitor to return all eligible hosts (ignore isMaster latency).
• Add a failpoint to NetworkInterfaceTL that forces startCommand to target the eligible hosts in alphabetical order (hedging_metrics_server_status.js assumes that it always target the primary first which is not always true).