Initialize pod resource allocation checkpoint manager to noop

This avoids accidentally introducing null pointer access if manager
functions were called outside of InPlacePodVerticalScaling feature gate.

pkg/kubelet/status/state/state_checkpoint.go

@@ -177,3 +177,50 @@ func (sc *stateCheckpoint) ClearState() error {
 	sc.cache.ClearState()
 	return sc.storeState()
 }
+
+type noopStateCheckpoint struct{}
+
+// NewNoopStateCheckpoint creates a dummy state checkpoint manager
+func NewNoopStateCheckpoint() State {
+	return &noopStateCheckpoint{}
+}
+
+func (sc *noopStateCheckpoint) GetContainerResourceAllocation(_ string, _ string) (v1.ResourceList, bool) {
+	return nil, false
+}
+
+func (sc *noopStateCheckpoint) GetPodResourceAllocation() PodResourceAllocation {
+	return nil
+}
+
+func (sc *noopStateCheckpoint) GetPodResizeStatus(_ string) (v1.PodResizeStatus, bool) {
+	return "", false
+}
+
+func (sc *noopStateCheckpoint) GetResizeStatus() PodResizeStatus {
+	return nil
+}
+
+func (sc *noopStateCheckpoint) SetContainerResourceAllocation(_ string, _ string, _ v1.ResourceList) error {
+	return nil
+}
+
+func (sc *noopStateCheckpoint) SetPodResourceAllocation(_ PodResourceAllocation) error {
+	return nil
+}
+
+func (sc *noopStateCheckpoint) SetPodResizeStatus(_ string, _ v1.PodResizeStatus) error {
+	return nil
+}
+
+func (sc *noopStateCheckpoint) SetResizeStatus(_ PodResizeStatus) error {
+	return nil
+}
+
+func (sc *noopStateCheckpoint) Delete(_ string, _ string) error {
+	return nil
+}
+
+func (sc *noopStateCheckpoint) ClearState() error {
+	return nil
+}

pkg/kubelet/status/status_manager.go

@@ -186,6 +186,9 @@ func isPodStatusByKubeletEqual(oldStatus, status *v1.PodStatus) bool {
 }
 
 func (m *manager) Start() {
+	// Initialize m.state to no-op state checkpoint manager
+	m.state = state.NewNoopStateCheckpoint()
+
 	// Create pod allocation checkpoint manager even if client is nil so as to allow local get/set of AllocatedResources & Resize
 	if utilfeature.DefaultFeatureGate.Enabled(features.InPlacePodVerticalScaling) {
 		stateImpl, err := state.NewStateCheckpoint(m.stateFileDirectory, podStatusManagerStateFile)