storage: TestIntegration_HMACKey failed

[flaky-bot]

This test failed!

To configure my behavior, see the Flaky Bot documentation.

If I'm commenting on this issue too often, add the flakybot: quiet label and
I will stop commenting.

---

commit: d2f33ab
buildURL: Build Status, Sponge
status: failed

Test output

    integration_test.go:4175: Failed to create HMACKey: Post "https://storage.googleapis.com/storage/v1/projects/dulcet-port-762/hmacKeys?alt=json&prettyPrint=false&serviceAccountEmail=kokoro%40dulcet-port-762.iam.gserviceaccount.com": oauth2: cannot fetch token: 503 Service Unavailable
        Response: {
          "error": {
            "code": 503,
            "message": "The service is currently unavailable.",
            "status": "UNAVAILABLE"
          }
        }

[flaky-bot]

Looks like this issue is flaky. 😟

I'm going to leave this open and stop commenting.

A human should fix and close this.

---

When run at the same commit (d2f33ab), this test passed in one build (Build Status, Sponge) and failed in another build (Build Status, Sponge).