updated embedding model

app.py

@@ -25,8 +25,8 @@ def is_valid_gemini_api_key(api_key):
 def prepare_query_engine(api_key):
   # Gemini Embeddings
   embed_model = GeminiEmbedding(
-      model="models/embedding-001",
-      title="Oppenheimer movie wikipedia",
+      model="models/embedding-004",
+      title="wikipedia page of the 'Oppenheimer' movie",
       embed_batch_size=16,
       api_key=api_key
   )