Automatic merge from submit-queue (batch tested with PRs 47065, 47157, 47143)

Use actual hostname when creating network e2e test pod

**What this PR does / why we need it**:
This changes a e2e framework network test Pod use the actual hostname value to match the `kubernetes.io/hostname` label in it's `NodeSelector`. Currently it assumes the Node name will match that hostname label which is not true in all environments.

**Which issue this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close that issue when PR gets merged)*: 
Fixes coreos/tectonic-installer#1018

**Release note**:

```release-note
NONE
```