cross-build should not use cli unless specified

[ericzzzzzzz]

• 9103 enabled users to run build with docker compatible daemon without docker cli, for non-cross-platform build.

• However, corss-platform builds still uses docker cli even users not specified, we should enable to use the docker-compatible backend build without cli for cross-platfrom builds as well.
• @ericzzzzzzz made some attempts, here is what we got
  • We can specify platform with buildOption when issuing Build request to docker backend, if docker backend host machine has qemu set-up,
  • We can do for minikube with minikube ssh "docker run --privileged --rm tonistiigi/binfmt --install all" for our github action ci
  • For our internal kokoro CI, it seems that we need to upgrade docker engine version as well to make cross-platform builds work without using buildx(docker cli). To upgrade docker engine, please see here : https://docs.docker.com/engine/install/ubuntu/

The ask in this issue, is to enable docker cross-platform builds without cli

[enihcam]

I have a similar situation here: I'm using custom buildCommand with buildah plus a remote private insecure image registry. I always get error Build Failed. Cannot connect to the Docker daemon at unix:///var/run/docker.sock. Check if docker is running.

any dirty workarounds? Thanks. @ericzzzzzzz