Update Node Monitor Grace Period default duration to 50s

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Update Test case value to be 50s by default

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pkg/controller/nodelifecycle/node_lifecycle_controller_test.go

@@ -52,7 +52,7 @@ import (
 )
 
 const (
-	testNodeMonitorGracePeriod = 40 * time.Second
+	testNodeMonitorGracePeriod = 50 * time.Second
 	testNodeStartupGracePeriod = 60 * time.Second
 	testNodeMonitorPeriod      = 5 * time.Second
 	testRateLimiterQPS         = float32(100000)