[status] Point to staging BigTable instance for Task Drivers

Task Drivers aren't in prod yet.

Bug: skia:
Change-Id: Ia8d4a601d084bad9142ec52721223c5cf3520c60
Reviewed-on: https://skia-review.googlesource.com/c/179736
Reviewed-by: Eric Boren <borenet@google.com>
Commit-Queue: Eric Boren <borenet@google.com>
diff --git a/status/go/status/main.go b/status/go/status/main.go
index 6b2f5d4..0d101a8 100644
--- a/status/go/status/main.go
+++ b/status/go/status/main.go
@@ -851,11 +851,12 @@
 	})
 
 	// Create the TaskDriver DB.
-	taskDriverDb, err = bigtable_db.NewBigTableDB(ctx, *btProject, *btInstance, ts)
+	taskDriverBtInstance := "staging" // Task Drivers aren't in prod yet.
+	taskDriverDb, err = bigtable_db.NewBigTableDB(ctx, *btProject, taskDriverBtInstance, ts)
 	if err != nil {
 		sklog.Fatal(err)
 	}
-	taskDriverLogs, err = logs.NewLogsManager(ctx, *btProject, *btInstance, ts)
+	taskDriverLogs, err = logs.NewLogsManager(ctx, *btProject, taskDriverBtInstance, ts)
 	if err != nil {
 		sklog.Fatal(err)
 	}