fix(storage): Address feedback on BidiWriteObject error handling

Author: kalragauri

google/cloud/storage/internal/grpc/configure_client_context.cc

@@ -20,6 +20,19 @@ namespace google {
 namespace cloud {
 namespace storage_internal {
 GOOGLE_CLOUD_CPP_INLINE_NAMESPACE_BEGIN
+namespace {
+void ApplyRoutingHeadersImpl(grpc::ClientContext& context,
+                             std::string const& bucket_name,
+                             RoutingHeaderOptions const& options) {
+  std::string params =
+      "bucket=" + google::cloud::internal::UrlEncode(bucket_name);
+  if (!options.routing_token.empty()) {
+    params += "&routing_token=" +
+              google::cloud::internal::UrlEncode(options.routing_token);
+  }
+  context.AddMetadata("x-goog-request-params", std::move(params));
+}
+}  // namespace
 
 auto constexpr kIdempotencyTokenHeader = "x-goog-gcs-idempotency-token";
 
@@ -46,25 +59,13 @@ void ApplyRoutingHeaders(
 void ApplyRoutingHeaders(grpc::ClientContext& context,
                          google::storage::v2::WriteObjectSpec const& spec,
                          RoutingHeaderOptions const& options) {
-  std::string params =
-      "bucket=" + google::cloud::internal::UrlEncode(spec.resource().bucket());
-  if (!options.routing_token.empty()) {
-    params += "&routing_token=" +
-              google::cloud::internal::UrlEncode(options.routing_token);
-  }
-  context.AddMetadata("x-goog-request-params", params);
+  ApplyRoutingHeadersImpl(context, spec.resource().bucket(), options);
 }
 
 void ApplyRoutingHeaders(grpc::ClientContext& context,
                          google::storage::v2::AppendObjectSpec const& spec,
                          RoutingHeaderOptions const& options) {
-  std::string params =
-      "bucket=" + google::cloud::internal::UrlEncode(spec.bucket());
-  if (!options.routing_token.empty()) {
-    params += "&routing_token=" +
-              google::cloud::internal::UrlEncode(options.routing_token);
-  }
-  context.AddMetadata("x-goog-request-params", params);
+  ApplyRoutingHeadersImpl(context, spec.bucket(), options);
 }
 
 void ApplyRoutingHeaders(grpc::ClientContext& context,