Update Vertex AI to include Gemini (#14670)

h/t to @lkuligin 
-  **Description:** added new models on VertexAI
  - **Twitter handle:** @lkuligin

---------

Co-authored-by: Leonid Kuligin <lkuligin@yandex.ru>
Co-authored-by: Harrison Chase <hw.chase.17@gmail.com>

libs/community/langchain_community/utilities/vertexai.py

@@ -11,6 +11,7 @@ from langchain_core.language_models.llms import BaseLLM, create_base_retry_decor
 if TYPE_CHECKING:
     from google.api_core.gapic_v1.client_info import ClientInfo
     from google.auth.credentials import Credentials
+    from vertexai.preview.generative_models import Image
 
 
 def create_retry_decorator(
@@ -37,7 +38,7 @@ def create_retry_decorator(
     return decorator
 
 
-def raise_vertex_import_error(minimum_expected_version: str = "1.36.0") -> None:
+def raise_vertex_import_error(minimum_expected_version: str = "1.38.0") -> None:
     """Raise ImportError related to Vertex SDK being not available.
 
     Args:
@@ -105,3 +106,19 @@ def get_client_info(module: Optional[str] = None) -> "ClientInfo":
         client_library_version=client_library_version,
         user_agent=f"langchain/{client_library_version}",
     )
+
+
+def load_image_from_gcs(path: str, project: Optional[str] = None) -> "Image":
+    """Loads im Image from GCS."""
+    try:
+        from google.cloud import storage
+    except ImportError:
+        raise ImportError("Could not import google-cloud-storage python package.")
+    from vertexai.preview.generative_models import Image
+
+    gcs_client = storage.Client(project=project)
+    pieces = path.split("/")
+    blobs = list(gcs_client.list_blobs(pieces[2], prefix="/".join(pieces[3:])))
+    if len(blobs) > 1:
+        raise ValueError(f"Found more than one candidate for {path}!")
+    return Image.from_bytes(blobs[0].download_as_bytes())