switch from YAML to JSON

src/main/java/com/redhat/training/ApiClient.java

@@ -15,7 +15,7 @@ import jakarta.ws.rs.core.MediaType;
 public interface ApiClient {
     @POST
     @Path("/namespaces/{namespace}/jobs/{job}")
-    @Consumes("application/yaml")
+    @Consumes("application/json")
     @Produces(MediaType.APPLICATION_JSON)
     String createJob(@HeaderParam("Authorization") String token,
                      @PathParam("namespace") String namespace,