Fix IVRNavigator to push AggregatedTextFrame when switching to conversation mode

tests/test_ivr_navigation.py

@@ -10,6 +10,7 @@ from unittest.mock import AsyncMock
 from pipecat.audio.vad.vad_analyzer import VADParams
 from pipecat.extensions.ivr.ivr_navigator import IVRProcessor
 from pipecat.frames.frames import (
+    AggregatedTextFrame,
     LLMFullResponseEndFrame,
     LLMMessagesUpdateFrame,
     LLMTextFrame,
@@ -339,7 +340,7 @@ class TestIVRNavigation(unittest.IsolatedAsyncioTestCase):
         ]
 
         expected_down_frames = [
-            LLMTextFrame,  # Should pass through unchanged
+            AggregatedTextFrame,  # LLMTextFrames aggregrated and converted to AggregatedTextFrame
             LLMFullResponseEndFrame,
         ]