[da-vinci][fast-client] Delete deprecated NativeMetadataRepository an…

…d StoreMetadata implementations (#1171)

1. Deleted DaVinciClientMetaStoreBasedRepository, DaVinciClientBasedMetadata, related configs and tests.
This was originally used by DaVinciClientBasedMetadata to retrieve metadata from the meta system
store for fast-client.

2. Deleted ThinClientBasedMetadata, configs and related tests. This was originally introduced as a
tactical fix to support running DVC and fast-client running in the same host.

clients/da-vinci-client/src/main/java/com/linkedin/davinci/repository/NativeMetadataRepository.java

@@ -1,15 +1,12 @@
 package com.linkedin.davinci.repository;
 
 import static com.linkedin.venice.ConfigKeys.CLIENT_SYSTEM_STORE_REPOSITORY_REFRESH_INTERVAL_SECONDS;
-import static com.linkedin.venice.ConfigKeys.CLIENT_USE_DA_VINCI_BASED_SYSTEM_STORE_REPOSITORY;
 import static com.linkedin.venice.system.store.MetaStoreWriter.KEY_STRING_SCHEMA_ID;
 import static com.linkedin.venice.system.store.MetaStoreWriter.KEY_STRING_STORE_NAME;
 import static java.lang.Thread.currentThread;
 
-import com.linkedin.davinci.client.factory.CachingDaVinciClientFactory;
 import com.linkedin.venice.client.exceptions.ServiceDiscoveryException;
 import com.linkedin.venice.client.store.ClientConfig;
-import com.linkedin.venice.client.store.ClientFactory;
 import com.linkedin.venice.common.VeniceSystemStoreType;
 import com.linkedin.venice.exceptions.MissingKeyInStoreMetadataException;
 import com.linkedin.venice.exceptions.VeniceException;
@@ -26,9 +23,7 @@
 import com.linkedin.venice.schema.SchemaEntry;
 import com.linkedin.venice.schema.rmd.RmdSchemaEntry;
 import com.linkedin.venice.schema.writecompute.DerivedSchemaEntry;
-import com.linkedin.venice.serialization.avro.AvroProtocolDefinition;
 import com.linkedin.venice.service.ICProvider;
-import com.linkedin.venice.stats.TehutiUtils;
 import com.linkedin.venice.system.store.MetaStoreDataType;
 import com.linkedin.venice.systemstore.schemas.StoreClusterConfig;
 import com.linkedin.venice.systemstore.schemas.StoreMetaKey;
@@ -41,7 +36,6 @@
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
-import java.util.Optional;
 import java.util.Set;
 import java.util.concurrent.CopyOnWriteArraySet;
 import java.util.concurrent.Executors;
@@ -122,31 +116,11 @@ public static NativeMetadataRepository getInstance(
       ClientConfig clientConfig,
       VeniceProperties backendConfig,
       ICProvider icProvider) {
-    if (backendConfig.getBoolean(CLIENT_USE_DA_VINCI_BASED_SYSTEM_STORE_REPOSITORY, false)) {
-      LOGGER.info(
-          "Initializing {} with {}",
-          NativeMetadataRepository.class.getSimpleName(),
-          DaVinciClientMetaStoreBasedRepository.class.getSimpleName());
-      ClientConfig clonedClientConfig = ClientConfig.cloneConfig(clientConfig)
-          .setStoreName(AvroProtocolDefinition.METADATA_SYSTEM_SCHEMA_STORE.getSystemStoreName())
-          .setSpecificValueClass(StoreMetaValue.class);
-      return new DaVinciClientMetaStoreBasedRepository(
-          clientConfig,
-          backendConfig,
-          new CachingDaVinciClientFactory(
-              clientConfig.getD2Client(),
-              clientConfig.getD2ServiceName(),
-              Optional.ofNullable(clientConfig.getMetricsRepository())
-                  .orElse(TehutiUtils.getMetricsRepository("davinci-client")),
-              backendConfig),
-          ClientFactory.getSchemaReader(clonedClientConfig, null));
-    } else {
-      LOGGER.info(
-          "Initializing {} with {}",
-          NativeMetadataRepository.class.getSimpleName(),
-          ThinClientMetaStoreBasedRepository.class.getSimpleName());
-      return new ThinClientMetaStoreBasedRepository(clientConfig, backendConfig, icProvider);
-    }
+    LOGGER.info(
+        "Initializing {} with {}",
+        NativeMetadataRepository.class.getSimpleName(),
+        ThinClientMetaStoreBasedRepository.class.getSimpleName());
+    return new ThinClientMetaStoreBasedRepository(clientConfig, backendConfig, icProvider);
   }
 
   @Override