There's a workaround by running -run=Test but this periodically
comes up as an issue, so have `go test` only run Test* to stem
the complaints.
Fixes#8000
AfterTest() has a delay that waits for runtime goroutines to exit;
CheckLeakedGoroutine does not. Since the test runner manages the
test cluster for examples, there is no delay between terminating
the cluster and checking for leaked goroutines. Instead, apply
Aftertest checking before running CheckLeakedGoroutine to let runtime
http goroutines finish.
Gyuho Lee