refactor: rename SessionInput.events to conversation_history for clarity

Author: brucearctor

src/google/adk/evaluation/eval_case.py

@@ -125,7 +125,7 @@ class SessionInput(EvalBaseModel):
   state: SessionState = Field(default_factory=dict)
   """The state of the session."""
 
-  events: Optional[list[Event]] = None
+  conversation_history: Optional[list[Event]] = None
   """Optional list of events to seed the session with prior conversation history.
 
   When provided, these events are appended to the session after creation but

src/google/adk/evaluation/evaluation_generator.py

@@ -567,8 +567,8 @@ async def _generate_inferences_from_root_agent(
 
     # Seed session with prior conversation history so that eval turns
     # run with realistic prior context without being scored.
-    if initial_session and initial_session.events:
-      for event in initial_session.events:
+    if initial_session and initial_session.conversation_history:
+      for event in initial_session.conversation_history:
         await session_service.append_event(session=session, event=event)
 
     if not artifact_service: