Onboard addon-resizer repository into automatic image pushes

[raywainman]

Which component are you using?:

/area addon-resizer

Is your feature request designed to solve a problem? If so describe the problem this feature should solve.:

Currently the release process requires someone to manually build an image and push it to a container repository.

Describe the solution you'd like.:

We should onboard into the standard image pushing flow.

Once we get this up and running for addon-resizer, we can do the same for VPA and CA.

[raywainman]

/assign raywainman

[adolfogottlieb]

/assign raywainman

[raywainman]

https://testgrid.k8s.io/sig-autoscaling-addon-resizer#post-autoscaler-push-addon-resizer-images shows the test grid with the image pushes.

They pushes are currently failing with this error:

#6 [2/2] COPY pod_nanny /
#6 ERROR: failed to calculate checksum of ref wxxtmvqpheia57lo3sj5pfxdo::2blfawtv8a9ckv9vhwule639y: "/pod_nanny": not found

[raywainman]

Looks like things are mostly working now. The build is able to generate all the images, it just times out now at the very end of the process on the Prow side. I've sent out another PR to increase build times.