fix: proper DGD prefix for naive fallback in DGDR (#6667)

Signed-off-by: hongkuanz <hongkuanz@nvidia.com>

components/src/dynamo/profiler/rapid.py

@@ -137,7 +137,7 @@ def _run_naive_fallback(
         "best_config_df": pd.DataFrame(),
         "best_latencies": {"ttft": 0.0, "tpot": 0.0, "request_latency": 0.0},
         "dgd_config": dgd_config,
-        "chosen_exp": None,
+        "chosen_exp": "agg",  # AIC's naive route always generate agg config
     }