revert(csharp/src/Telemetry): re-enable compile-time JSON serializer context for trace activity

csharp/src/Telemetry/Traces/Exporters/FileExporter/FileExporter.cs

@@ -21,7 +21,6 @@
 using System.IO;
 using System.Text;
 using System.Text.Json;
-using System.Text.Json.Serialization.Metadata;
 using System.Threading;
 using System.Threading.Channels;
 using System.Threading.Tasks;
@@ -39,12 +38,6 @@ internal class FileExporter : BaseExporter<Activity>
 
         private static readonly ConcurrentDictionary<string, Lazy<FileExporterInstance>> s_fileExporters = new();
         private static readonly byte[] s_newLine = Encoding.UTF8.GetBytes(Environment.NewLine);
-        private static readonly JsonSerializerOptions s_serializerOptions = new()
-        {
-            TypeInfoResolver = JsonTypeInfoResolver.Combine(
-                SerializableActivitySerializerContext.Default,
-                new DefaultJsonTypeInfoResolver())
-        };
 
         private readonly TracingFile _tracingFile;
         private readonly string _fileBaseName;
@@ -158,9 +151,7 @@ private static async Task ProcessActivitiesAsync(FileExporter fileExporter, Canc
                     SerializableActivity serializableActivity = new(activity);
                     await JsonSerializer.SerializeAsync(
                         stream,
-                        serializableActivity,
-                        s_serializerOptions,
-                        cancellationToken: cancellationToken).ConfigureAwait(false);
+                        serializableActivity, cancellationToken: cancellationToken).ConfigureAwait(false);
                     stream.Write(s_newLine, 0, s_newLine.Length);
                     stream.Position = 0;
 

csharp/src/Telemetry/Traces/Listeners/FileListener/ActivityProcessor.cs

@@ -20,7 +20,6 @@
 using System.IO;
 using System.Text;
 using System.Text.Json;
-using System.Text.Json.Serialization.Metadata;
 using System.Threading;
 using System.Threading.Channels;
 using System.Threading.Tasks;
@@ -30,12 +29,6 @@ namespace Apache.Arrow.Adbc.Telemetry.Traces.Listeners.FileListener
     internal sealed class ActivityProcessor : IDisposable
     {
         private static readonly byte[] s_newLine = Encoding.UTF8.GetBytes(Environment.NewLine);
-        private static readonly JsonSerializerOptions s_serializerOptions = new()
-        {
-            TypeInfoResolver = JsonTypeInfoResolver.Combine(
-                SerializableActivitySerializerContext.Default,
-                new DefaultJsonTypeInfoResolver())
-        };
         private Task? _processingTask;
         private readonly Channel<Activity> _channel;
         private readonly Func<Stream, CancellationToken, Task> _streamWriterFunc;
@@ -98,9 +91,7 @@ private async Task ProcessActivitiesAsync(CancellationToken cancellationToken)
                     SerializableActivity serializableActivity = new(activity);
                     await JsonSerializer.SerializeAsync(
                         stream,
-                        serializableActivity,
-                        s_serializerOptions,
-                        cancellationToken: cancellationToken).ConfigureAwait(false);
+                        serializableActivity, cancellationToken: cancellationToken).ConfigureAwait(false);
                     stream.Write(s_newLine, 0, s_newLine.Length);
                     stream.Position = 0;