Increase e2e test timeout. (#908)
Increase e2e test timeout. (#908)

Looks like 2s is too aggressive, and we can see these log lines:

```
error issuing verification code: sending request: Post
"https://adminapi-lilkbg3hpq-uc.a.run.app/api/issue": net/http: request
canceled (Client.Timeout exceeded while awaiting headers)
```
google/exposure-notifications-verification-server,google/exposure-notifications-verification-server,google/exposure-notifications-verification-server,google/exposure-notifications-verification-server