Don't use default serializer for eid logger post

backend/src/Designer/TypedHttpClients/EidLogger/EidLoggerClient.cs

@@ -1,11 +1,18 @@
 using System.Net.Http;
+using System.Net.Mime;
+using System.Text;
+using System.Text.Json;
 using System.Threading.Tasks;
 
 namespace Altinn.Studio.Designer.TypedHttpClients.EidLogger;
 
 public class EidLoggerClient : IEidLoggerClient
 {
     private readonly HttpClient _httpClient;
+    private readonly JsonSerializerOptions _jsonSerializerOptions = new JsonSerializerOptions
+    {
+        PropertyNamingPolicy = JsonNamingPolicy.CamelCase
+    };
 
     public EidLoggerClient(HttpClient httpClient)
     {
@@ -14,7 +21,11 @@ public EidLoggerClient(HttpClient httpClient)
 
     public async Task Log(EidLogRequest request)
     {
-        var response = await _httpClient.PostAsJsonAsync("eid-event-log", request);
+        using var payloadContent = new StringContent(JsonSerializer.Serialize(request, _jsonSerializerOptions),
+            Encoding.UTF8,
+            MediaTypeNames.Application.Json);
+
+        using var response = await _httpClient.PostAsync("eid-event-log", payloadContent);
         response.EnsureSuccessStatusCode();
     }
 }