Automatic merge from submit-queue (batch tested with PRs 62495, 63003, 62829, 62151, 62002). If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.
[e2e ingress-gce] Fix race condition for appending services and ingresses
**What this PR does / why we need it**:
From https://github.com/kubernetes/ingress-gce/issues/219, how the test appends services and ingresses is not thread-safe. This PR fixes it by using channel.
**Which issue(s) this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close the issue(s) when PR gets merged)*:
Fixes #https://github.com/kubernetes/ingress-gce/issues/219
**Special notes for your reviewer**:
/assign @nicksardo
I picked this up as it is fun :) Hoping you haven't worked on it yet.
**Release note**:
```release-note
NONE
```