ASP-2043: Add serviceConfig support to GrpcChannelConfig for gRPC built-in retry

- Add optional serviceConfig field to GrpcChannelConfig
- Wire defaultServiceConfig() + enableRetry() in GrpcChannelRegistry when serviceConfig is set

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

AI-Session-Id: 75f3864c-dc2c-4e44-b4f3-b23c980f2ea6
AI-Tool: claude-code
AI-Model: unknown

Author: kunalvaswani123

grpc-client-utils/src/main/java/org/hypertrace/core/grpcutils/client/GrpcChannelConfig.java

@@ -2,6 +2,7 @@
 
 import io.grpc.ClientInterceptor;
 import java.util.List;
+import java.util.Map;
 import lombok.Builder;
 import lombok.Singular;
 import lombok.Value;
@@ -12,4 +13,6 @@ public class GrpcChannelConfig {
   Integer maxInboundMessageSize;
 
   @Singular List<ClientInterceptor> clientInterceptors;
+
+  Map<String, Object> serviceConfig;
 }

grpc-client-utils/src/main/java/org/hypertrace/core/grpcutils/client/GrpcChannelRegistry.java

@@ -90,6 +90,9 @@ protected ManagedChannel configureAndBuildChannel(
     if (config.getMaxInboundMessageSize() != null) {
       builder.maxInboundMessageSize(config.getMaxInboundMessageSize());
     }
+    if (config.getServiceConfig() != null) {
+      builder.defaultServiceConfig(config.getServiceConfig()).enableRetry();
+    }
     this.registryConfig.getDefaultInterceptors().forEach(builder::intercept);
     return builder.intercept(config.getClientInterceptors()).build();
   }