tests: HeartbeatTime=10s to reduce flakyness

Do this for all tests by changing this in TestMain.

Signed-off-by: Sugu Sougoumarane <ssougou@gmail.com>

go/vt/vttablet/tabletserver/vstreamer/main_test.go

@@ -21,6 +21,7 @@ import (
  "fmt"
  "os"
  "testing"
+ "time"
 
  "vitess.io/vitess/go/vt/vttablet/tabletserver/vstreamer/testenv"
 )
@@ -53,6 +54,12 @@ func TestMain(m *testing.M) {
  engine.Open(env.KeyspaceName, env.Cells[0])
  defer engine.Close()
 
+ // GH actions machines sometimes exhibit multi-second delays on replication.
+ // So, give a generously high value for heartbeat time for all tests.
+ saveHeartbeat := HeartbeatTime
+ defer func() { HeartbeatTime = saveHeartbeat }()
+ HeartbeatTime = 10 * time.Second
+
  return m.Run()
  }()
  os.Exit(exitCode)