Add logging for generate artifact hashes

Reviewed By: alunyov

Differential Revision: D51407825

fbshipit-source-id: ca51fd5fe43970f57a3632b8ac4dbb77b3511291

compiler/crates/relay-compiler/src/build_project/mod.rs

@@ -381,7 +381,13 @@ pub async fn commit_project(
     };
 
     let artifacts_file_hash_map = match &config.get_artifacts_file_hash_map {
-        Some(get_fn) => get_fn(&artifacts).await,
+        Some(get_fn) => {
+            let get_artifacts_file_hash_map_timer =
+                log_event.start("get_artifacts_file_hash_map_time");
+            let res = get_fn(&artifacts).await;
+            log_event.stop(get_artifacts_file_hash_map_timer);
+            res
+        }
         _ => None,
     };