indexer-alt: fix kv_feature_flags name (MystenLabs#20284)

## Description
Fixing copypasta

## Test plan

:eyes:

---

## Release notes

Check each box that your changes affect. If none of the boxes relate to
your changes, release notes aren't required.

For each box you select, include information after the relevant heading
that describes the impact of your changes that a user might notice and
any actions they must take to implement updates.

- [ ] Protocol: 
- [ ] Nodes (Validators and Full nodes): 
- [ ] Indexer: 
- [ ] JSON-RPC: 
- [ ] GraphQL: 
- [ ] CLI: 
- [ ] Rust SDK:
- [ ] REST API:

crates/sui-indexer-alt/src/handlers/kv_feature_flags.rs

@@ -18,7 +18,7 @@ use crate::{
 pub struct KvFeatureFlags(pub StoredGenesis);
 
 impl Processor for KvFeatureFlags {
-    const NAME: &'static str = "kv_protocol_configs";
+    const NAME: &'static str = "kv_feature_flags";
     type Value = StoredFeatureFlag;
 
     fn process(&self, checkpoint: &Arc<CheckpointData>) -> Result<Vec<Self::Value>> {