Automatic merge from submit-queue (batch tested with PRs 44722, 44704, 44681, 44494, 39732)
prevent installation of docker from upstream
**What this PR does / why we need it**: Disallows installation of upstream docker from PPA in the Juju kubernetes-worker charm.
**Which issue this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close that issue when PR gets merged)*: fixes #
**Special notes for your reviewer**:
**Release note**:
```release-note
Disallows installation of upstream docker from PPA in the Juju kubernetes-worker charm.
```