Add encrypted docker token to stage cloud build

Signed-off-by: Adolfo García Veytia (Puerco) <adolfo.garcia@uservers.net>

gcb/stage/cloudbuild.yaml

@@ -15,6 +15,7 @@ secrets:
 - kmsKeyName: projects/k8s-releng-prod/locations/global/keyRings/release/cryptoKeys/encrypt-0
   secretEnv:
     GITHUB_TOKEN: CiQAIkWjMMb2OjCHCt1hHer4ZBqqD1Mj7+dfTpvkkuzS64nrGm0SUQBLz1D+4Zwp6te6JByO/zvGpHMhW6/i3BJMRYXtNTkyBGMnZuH+J3gQfhcGL2HXjr75lHaCxF4bxPr45xen5D/Kk1+paL+XpOU3KJIADy7uGQ==
+    DOCKERHUB_TOKEN: CiQAIkWjMJDKU6Hu3pJIBf31dIl7xJQQEiccN7k1cCzGadGoT2gSTQBLz1D+uc9PMusYnFvXtJi25OqEUktDJs28d09jDyj9gcyTx9iX/JvOE3Dn2qnhrjwrUMk5bBhFjR7dHCr4mJgEVD5dXrd6yLGbDBu2
 
 steps:
 - name: gcr.io/cloud-builders/git