set timeout for waitFor function (#1196)
set timeout for waitFor function (#1196)

Automatic merge from submit-queue

set timeout for waitFor function

otherwise it could wait infinitely, causing unexpected test timeout.

See https://github.com/istio/istio/issues/633

**Release note**:

```release-note
none
```

Former-commit-id: b8c76ac69927515c15e5ec62f39f89961106fb22
sebastienvas/istio,mandarjog/istio,frankbu/istio,geeknoid/istio,smawson/istio,smawson/istio,smawson/istio,mandarjog/istio,geeknoid/istio,istio/istio,geeknoid/istio,istio/istio,mandarjog/istio,geeknoid/istio,sebastienvas/istio,frankbu/istio,smawson/istio,mandarjog/istio,sebastienvas/istio,sebastienvas/istio,frankbu/istio,istio/istio,frankbu/istio,mandarjog/istio,smawson/istio,geeknoid/istio,smawson/istio,istio/istio,geeknoid/istio,sebastienvas/istio,frankbu/istio,frankbu/istio,istio/istio