chore: GenAI - Decoupled generative_models from rag

PiperOrigin-RevId: 642416638

Author: Ark-kun

vertexai/generative_models/_generative_models.py

@@ -49,7 +49,6 @@
 import warnings
 
 if TYPE_CHECKING:
-    from vertexai.preview import rag
     from vertexai._caching import _caching as caching
 
 try:
@@ -1464,7 +1463,7 @@ def from_function_declarations(
     @classmethod
     def from_retrieval(
         cls,
-        retrieval: Union["grounding.Retrieval", "rag.Retrieval"],
+        retrieval: Union["preview_grounding.Retrieval"],
     ) -> "Tool":
         raw_tool = gapic_tool_types.Tool(retrieval=retrieval._raw_retrieval)
         return cls._from_gapic(raw_tool=raw_tool)

vertexai/preview/rag/rag_store.py

@@ -22,9 +22,10 @@
 from google.cloud.aiplatform import initializer
 from vertexai.preview.rag.utils import _gapic_utils
 from vertexai.preview.rag.utils.resources import RagResource
+from vertexai.preview import generative_models
 
 
-class Retrieval:
+class Retrieval(generative_models.grounding.Retrieval):
     """Defines a retrieval tool that a model can call to access external knowledge."""
 
     def __init__(