[2.12] Add 1.16.14 and 1.16.15 support (#6583)

* Use k8s.gcr.io for kubernetes related images (#5764)

* Use k8s.gcr.io for kubernetes related images

* Use k8s.gcr.io in inventory sample

* [2.12] Update hashes and set default version to 1.16.14

* [2.12] Update hashes and set default version to 1.16.15

Co-authored-by: Florent Monbillard <f.monbillard@gmail.com>