[PSM Interop] update td bootstrap generator image for prod tests (#34206)

This change is to update the TD bootstrap generator for prod tests. This
is part of the TD release process. The new image has already been merged
to staging and tested locally in google3.

cc: @sergiitk PTAL.

tools/run_tests/xds_k8s_test_driver/config/common.cfg

@@ -1,6 +1,5 @@
 --resource_prefix=psm-interop
-# https://github.com/GoogleCloudPlatform/traffic-director-grpc-bootstrap/releases/tag/v0.14.0
+--td_bootstrap_image=gcr.io/grpc-testing/td-grpc-bootstrap:d47f36f78aef8fe9d67303be1aba480f2fe9a77c
---td_bootstrap_image=gcr.io/grpc-testing/td-grpc-bootstrap:d6baaf7b0e0c63054ac4d9bedc09021ff261d599
 
 # The canonical implementation of the xDS test server.
 # Can be used in tests where language-specific xDS test server does not exist,