Make nodename test more consistent (#12330)

To determine when everything was stable, we couldn't just query the nodename since they aren't API visible by design. Instead, we were using a proxy piece of information which was bumping the epoch and waiting for everyone to observe that. This works for making source Node 0 and Node 1 had pinged, and Node 0 and Node 2 had pinged, but did not guarantee that Node 1 and Node 2 had pinged. Although unlikely, this can cause this failure message. To fix it I hijacked hostnames and used its validation that it has been propagated, since we know that it is stable.

I also noticed while stress testing this sometimes the test took almost 4.5 seconds to finish, which is really close to the current 5 second limit of the log check, so I bumped that up as well just to make it a bit more consistent.