assistant: Fix Google AI provider not respecting low_speed_timeout_in_seconds (#17423)

Release Notes:

- Fixed an issue when using Google Gemini models, where the setting
`low_speed_timeout_in_seconds` was not respected

crates/collab/src/llm.rs

@@ -380,6 +380,7 @@ async fn perform_completion(
                 google_ai::API_URL,
                 api_key,
                 serde_json::from_str(&params.provider_request.get())?,
+                None,
             )
             .await?;
 

crates/collab/src/rpc.rs

@@ -4540,6 +4540,7 @@ async fn count_language_model_tokens(
                 google_ai::API_URL,
                 api_key,
                 serde_json::from_str(&request.request)?,
+                None,
             )
             .await?
         }