KeyVault tests take long in playback

[pakrym]

  √ DeleteRsaHsmKey [22s 475ms]
  √ DeleteEcHsmKey [18s 73ms]
  √ GetDeletedRsaHsmKey [14s 24ms]
  √ RecoverDeletedEcHsmKey [28s 676ms]

cc @heaths

[heaths]

We have some mandatory waits for anything deletion-related (can take a while to actually delete on the backend), so some of these may not be skipping the duration that for playback.

[heaths]

I was running into this while fixing another bug, so I fixed it now (it was as I thought about the polling interval).