fixing references to re-enable guardrail callback (#299)

not sure how to add a test to this, since all tests that currently
address "GUARDRAIL_INTERVENED" messages do not cover the callback
section

this is related to
#78

libs/aws/langchain_aws/llms/bedrock.py

@@ -39,7 +39,7 @@
 )
 
 AMAZON_BEDROCK_TRACE_KEY = "amazon-bedrock-trace"
-GUARDRAILS_BODY_KEY = "amazon-bedrock-guardrailAssessment"
+GUARDRAILS_BODY_KEY = "amazon-bedrock-guardrailAction"
 HUMAN_PROMPT = "\n\nHuman:"
 ASSISTANT_PROMPT = "\n\nAssistant:"
 ALTERNATION_ERROR = (
@@ -886,7 +886,7 @@ def _get_bedrock_services_signal(self, body: dict) -> dict:
         }
 
     def _is_guardrails_intervention(self, body: dict) -> bool:
-        return body.get(GUARDRAILS_BODY_KEY) == "GUARDRAIL_INTERVENED"
+        return body.get(GUARDRAILS_BODY_KEY) == "INTERVENED"
 
     def _prepare_input_and_invoke_stream(
         self,