Fix S3 presigned URL upload 403 error by setting Content-Type header

The Conductor server's AWS SDK v2 upgrade (v3.21.17+) now includes
content-type in S3 presigned URL signatures. The client must send
a matching Content-Type header or S3 rejects the upload with 403.

Fixes conductor-oss/conductor#694

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: Naomi Most

conductor-client/src/main/java/com/netflix/conductor/client/http/PayloadStorage.java

@@ -93,6 +93,7 @@ public void upload(String uri, InputStream payload, long payloadSize) {
             connection = (HttpURLConnection) url.openConnection();
             connection.setDoOutput(true);
             connection.setRequestMethod("PUT");
+            connection.setRequestProperty("Content-Type", "application/json");
 
             try (BufferedOutputStream bufferedOutputStream = new BufferedOutputStream(connection.getOutputStream())) {
                 byte[] buffer = new byte[BUFFER_SIZE];