Automatic merge from submit-queue (batch tested with PRs 49019, 48919, 49040, 49018, 48874)
Set default snap channel on charms to 1.7 stable
**What this PR does / why we need it**: This PR sets the default snap channel on charms to 1.7/stable.
This addresses problems where the the user might want to deploy the charm and get the same kubernetes version found on the bundles.
**Which issue this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close that issue when PR gets merged)*: fixes https://github.com/juju-solutions/bundle-canonical-kubernetes/issues/305
**Special notes for your reviewer**:
**Release note**:
```Set default snap channel on charms to 1.7/stable
```
013d37d881