Sign an attestation for the proxy build
Sign an attestation for the proxy build

This signs an attestation that the proxy image was built by cloud build,
allowing the image to be used on a bin-auth restricted kubernetes cluster.

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=242917524

google/nomulus,google/nomulus,google/nomulus,google/nomulus,google/nomulus,google/nomulus