Do not consider pod PreemptionPolicy while determining whether pod is expendable

Change #6577 added a support for considering preemption policies into expendable pods evaluation, this is not correct as this propepty describes whether the created pod can evict other pods - thus should be considered only within scheduler and its framework. This change removes the policy out of the consideration

Author: mtrqq

cluster-autoscaler/core/utils/expendable.go

@@ -64,7 +64,5 @@ func FilterOutExpendablePods(pods []*apiv1.Pod, expendablePodsPriorityCutoff int
 
 // IsExpendablePod tests if pod is expendable for give priority cutoff
 func IsExpendablePod(pod *apiv1.Pod, expendablePodsPriorityCutoff int) bool {
-	preemptLowerPriority := pod.Spec.PreemptionPolicy == nil || *pod.Spec.PreemptionPolicy == apiv1.PreemptLowerPriority
-	lowPriority := pod.Spec.Priority != nil && int(*pod.Spec.Priority) < expendablePodsPriorityCutoff
-	return preemptLowerPriority && lowPriority
+	return pod.Spec.Priority != nil && int(*pod.Spec.Priority) < expendablePodsPriorityCutoff
 }

cluster-autoscaler/core/utils/expendable_test.go

@@ -88,7 +88,7 @@ func TestFilterOutExpendablePods(t *testing.T) {
 	assert.Equal(t, podWaitingForPreemption2, res[2])
 }
 
-func TestIsExpandablePod(t *testing.T) {
+func TestIsExpendablePod(t *testing.T) {
 	preemptLowerPriorityPolicy := apiv1.PreemptLowerPriority
 	neverPolicy := apiv1.PreemptNever
 
@@ -150,7 +150,7 @@ func TestIsExpandablePod(t *testing.T) {
 			name:   "pod priority set, never preemption policy, higher cutoff",
 			pod:    withPodPriority(BuildTestPod("p", 0, 0), -1, &neverPolicy),
 			cutoff: 0,
-			want:   false,
+			want:   true,
 		},
 		{
 			name:   "pod priority set, never preemption policy, equal cutoff",