Make feature gate for sig-apps/2255-pod-cost consistent with docs

The feature gate name for pod deletion cost was mentioned as ReplicaSetPodDeletionCost.
According to the docs and https://github.com/kubernetes/kubernetes/blob/9f7e079a5b0fc689aa7847ec8e5e189cac93c033/pkg/features/kube_features.go#L617
the feature gate name should be PodDeletionCost.

Signed-off-by: Madhav Jivrajani <[email protected]>

Author: MadhavJivrajani

keps/sig-apps/2255-pod-cost/README.md

@@ -169,7 +169,7 @@ N/A
 
 * **How can this feature be enabled / disabled in a live cluster?**
   - [x] Feature gate (also fill in values in `kep.yaml`)
-    - Feature gate name: ReplicaSetPodDeletionCost
+    - Feature gate name: PodDeletionCost
     - Components depending on the feature gate: kube-controller-manager
   - [ ] Other
     - Describe the mechanism:

keps/sig-apps/2255-pod-cost/kep.yaml

@@ -38,7 +38,7 @@ milestone:
 # The following PRR answers are required at alpha release
 # List the feature gate name and the components for which it must be enabled
 feature-gates:
- - name: ReplicaSetPodDeletionCost
+ - name: PodDeletionCost
    components:
      - kube-controller-manager
 disable-supported: true