[Bug][Go SDK]: Dataflow status polling too optimistic

### What happened?

Polling for pipeline results from Dataflow can spuriously cause the local task to be marked as failed if the RPC itself fails.

```
2022/09/30 11:05:26 Job still running ...
ptest.go:108: Failed to execute job: failed to get job
caused by:
googleapi: Error 503: Deadline exceeded, backendError
```

Unless there's an auth error, the code should simply retry with backoff a few times, and at least annotate the error with that it's not a real pipeline job failure.

https://github.com/apache/beam/blob/master/sdks/go/pkg/beam/runners/dataflow/dataflowlib/job.go#L246

### Issue Priority

Priority: 3

### Issue Component

Component: sdk-go