Automatic merge from submit-queue. 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>.
Add custom metrics e2e test with two metrics.
**What this PR does / why we need it**:
Adds an e2e test for HPA, where a deployment is scaled based on two custom metrics.
**Release note**:
```
NONE
```