refactor(tracing): streamline input extraction in OCI tracer

- Updated the `extract_inputs_from_chat_details` function to convert message roles to lowercase for consistency with OpenAI format.
- Removed commented-out code related to system message extraction to enhance code clarity and maintainability.

Author: viniciusdsmello

src/openlayer/lib/integrations/oci_tracer.py

@@ -9,8 +9,6 @@
 try:
     import oci
     from oci.generative_ai_inference import GenerativeAiInferenceClient
-    from oci.generative_ai_inference.models import GenericChatRequest, ChatDetails
-
     HAVE_OCI = True
 except ImportError:
     HAVE_OCI = False
@@ -380,8 +378,8 @@ def extract_inputs_from_chat_details(chat_details) -> Dict[str, Any]:
             if hasattr(chat_request, "messages") and chat_request.messages:
                 messages = []
                 for msg in chat_request.messages:
-                    # Extract role
-                    role = getattr(msg, "role", "USER")
+                    # Extract role and convert to OpenAI format (lowercase)
+                    role = getattr(msg, "role", "USER").lower()
 
                     # Extract content text
                     content_text = ""
@@ -402,10 +400,6 @@ def extract_inputs_from_chat_details(chat_details) -> Dict[str, Any]:
 
                 inputs["prompt"] = messages
 
-            # Extract system message if present
-            if hasattr(chat_request, "system_message") and chat_request.system_message:
-                inputs["system"] = chat_request.system_message
-
             # Extract tools if present
             if hasattr(chat_request, "tools") and chat_request.tools:
                 inputs["tools"] = chat_request.tools