AI rule node: change default prompts

rule-engine/rule-engine-components/src/main/java/org/thingsboard/rule/engine/ai/TbAiNodeConfiguration.java

@@ -49,13 +49,8 @@ public class TbAiNodeConfiguration implements NodeConfiguration<TbAiNodeConfigur
     @Override
     public TbAiNodeConfiguration defaultConfiguration() {
         var configuration = new TbAiNodeConfiguration();
-        configuration.setSystemPrompt("""
-                Take a deep breath and work on this step by step.
-                You are an industry-leading IoT domain expert with deep experience in telemetry data analysis.
-                Your task is to complete the user-provided task or answer a question.
-                You may use additional context information called "Rule engine message payload", "Rule engine message metadata" and "Rule engine message type".
-                Your response must be in JSON format.""");
-        configuration.setUserPrompt("Tell me a joke");
+        configuration.setSystemPrompt("You are helpful assistant. Your response must be in JSON format.");
+        configuration.setUserPrompt("Tell me a joke.");
         return configuration;
     }