[launcher] update base image (#670)

Author: jkl73

launcher/cloudbuild.yaml

@@ -6,7 +6,7 @@ substitutions:
   '_OUTPUT_IMAGE_SUFFIX': ''
   '_OUTPUT_IMAGE_FAMILY': ''
   '_BUCKET_NAME': '${PROJECT_ID}_cloudbuild'
-  '_VG_BASE_IMAGE': 'cos-125-19216-104-149'
+  '_VG_BASE_IMAGE': 'cos-125-19216-220-9'
 
 steps:
 # determine the base image