[fast-client] Change defaults to production values (linkedin#2895)

Enable long-tail retry by default for single-get and batch-get, matching
the values run in production:
- longTailRetryEnabledForSingleGet: false -> true
- longTailRetryEnabledForBatchGet: false -> true

Thresholds are unchanged because they already match production (single-get
1ms; batch-get falls back to the existing range-based threshold map when the
fixed threshold is 0). Compute long-tail retry stays disabled, also matching
production. The behavior is bounded by the retry budget, which is already
enabled by default (10%).

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: kvargha

clients/venice-client/src/main/java/com/linkedin/venice/fastclient/ClientConfig.java

@@ -449,10 +449,10 @@ public static class ClientConfigBuilder<K, V, T extends SpecificRecord> {
     private long metadataRefreshIntervalInSeconds = -1;
     private long metadataConnWarmupTimeoutInSeconds = -1;
 
-    private boolean longTailRetryEnabledForSingleGet = false;
+    private boolean longTailRetryEnabledForSingleGet = true;
     private int longTailRetryThresholdForSingleGetInMicroSeconds = 1000; // 1ms.
 
-    private boolean longTailRetryEnabledForBatchGet = false;
+    private boolean longTailRetryEnabledForBatchGet = true;
     private int longTailRetryThresholdForBatchGetInMicroSeconds = 0;
 
     private String longTailRangeBasedRetryThresholdForBatchGetInMilliSeconds =

internal/venice-test-common/src/integrationTest/java/com/linkedin/venice/fastclient/AvroStoreClientEndToEndTest.java

@@ -209,7 +209,9 @@ public void testFastClientGet(
     ClientConfig.ClientConfigBuilder clientConfigBuilder =
         new ClientConfig.ClientConfigBuilder<>().setStoreName(storeName)
             .setR2Client(r2Client)
-            .setDualReadEnabled(dualRead);
+            .setDualReadEnabled(dualRead)
+            .setLongTailRetryEnabledForSingleGet(false)
+            .setLongTailRetryEnabledForBatchGet(false);
     // Test HAR algorithm in this test.
     Set<String> harClusters = new HashSet<>();
     harClusters.add(veniceCluster.getServerD2ServiceName());
@@ -314,7 +316,9 @@ public void testFastClientGetWithDifferentHTTPVariants(
     ClientConfig.ClientConfigBuilder clientConfigBuilder =
         new ClientConfig.ClientConfigBuilder<>().setStoreName(storeName)
             .setR2Client(r2Client)
-            .setDualReadEnabled(false);
+            .setDualReadEnabled(false)
+            .setLongTailRetryEnabledForSingleGet(false)
+            .setLongTailRetryEnabledForBatchGet(false);
     // single get
     Consumer<MetricsRepository> fastClientStatsValidation =
         metricsRepository -> validateSingleGetMetrics(metricsRepository, false, false);

internal/venice-test-common/src/integrationTest/java/com/linkedin/venice/fastclient/BatchGetAvroStoreClientTest.java

@@ -131,7 +131,9 @@ public void testBatchGetGenericClient(boolean retryEnabled, StoreMetadataFetchMo
     ClientConfig.ClientConfigBuilder clientConfigBuilder =
         new ClientConfig.ClientConfigBuilder<>().setStoreName(storeName)
             .setR2Client(r2Client)
-            .setDualReadEnabled(false);
+            .setDualReadEnabled(false)
+            .setLongTailRetryEnabledForSingleGet(false)
+            .setLongTailRetryEnabledForBatchGet(false);
 
     if (retryEnabled) {
       // enable retry to test the code path: to mimic retry in integration tests
@@ -169,7 +171,9 @@ public void testBatchGetSpecificClient(StoreMetadataFetchMode storeMetadataFetch
     ClientConfig.ClientConfigBuilder clientConfigBuilder =
         new ClientConfig.ClientConfigBuilder<>().setStoreName(storeName)
             .setR2Client(r2Client)
-            .setDualReadEnabled(false);
+            .setDualReadEnabled(false)
+            .setLongTailRetryEnabledForSingleGet(false)
+            .setLongTailRetryEnabledForBatchGet(false);
 
     VeniceMetricsRepository metricsRepository = createVeniceMetricsRepository(true);
     AvroSpecificStoreClient<String, TestValueSchema> specificFastClient =
@@ -199,7 +203,9 @@ public void testStreamingBatchGetGenericClient(boolean retryEnabled, StoreMetada
     ClientConfig.ClientConfigBuilder clientConfigBuilder =
         new ClientConfig.ClientConfigBuilder<>().setStoreName(storeName)
             .setR2Client(r2Client)
-            .setDualReadEnabled(false);
+            .setDualReadEnabled(false)
+            .setLongTailRetryEnabledForSingleGet(false)
+            .setLongTailRetryEnabledForBatchGet(false);
 
     if (retryEnabled) {
       // enable retry to test the code path: to mimic retry in integration tests
@@ -257,7 +263,9 @@ public void testStreamingBatchGetLimit() throws Exception {
     ClientConfig.ClientConfigBuilder clientConfigBuilder =
         new ClientConfig.ClientConfigBuilder<>().setStoreName(storeName)
             .setR2Client(r2Client)
-            .setDualReadEnabled(false);
+            .setDualReadEnabled(false)
+            .setLongTailRetryEnabledForSingleGet(false)
+            .setLongTailRetryEnabledForBatchGet(false);
 
     VeniceMetricsRepository metricsRepository = createVeniceMetricsRepository(true);
     AvroGenericStoreClient<String, GenericRecord> genericFastClient =
@@ -301,7 +309,9 @@ public void testStreamingBatchGetWithCallbackGenericClient(
     ClientConfig.ClientConfigBuilder clientConfigBuilder =
         new ClientConfig.ClientConfigBuilder<>().setStoreName(storeName)
             .setR2Client(r2Client)
-            .setDualReadEnabled(false);
+            .setDualReadEnabled(false)
+            .setLongTailRetryEnabledForSingleGet(false)
+            .setLongTailRetryEnabledForBatchGet(false);
 
     if (retryEnabled) {
       // enable retry to test the code path: to mimic retry in integration tests