Replace deprecated controller-runtime signals package location

Kubernetes controller-runtime dependency deprecated the old location
operator-framework/operator-sdk#1876

Replace import sigs.k8s.io/controller-runtime/pkg/runtime/signals
with sigs.k8s.io/controller-runtime/pkg/manager/signals

cmd/manager/main.go

@@ -27,9 +27,9 @@ import (
 	"k8s.io/apimachinery/pkg/util/intstr"
 	"sigs.k8s.io/controller-runtime/pkg/client/config"
 	"sigs.k8s.io/controller-runtime/pkg/manager"
+	"sigs.k8s.io/controller-runtime/pkg/manager/signals"
 	crmetrics "sigs.k8s.io/controller-runtime/pkg/metrics"
 	logf "sigs.k8s.io/controller-runtime/pkg/runtime/log"
-	"sigs.k8s.io/controller-runtime/pkg/runtime/signals"
 )
 
 // Change below variables to serve metrics on different host or port.