ubuntu_docker_test failed on ARM64 system

This issue can be divided into 2 parts:

1. docker: Error response from daemon: Get https://registry-1.docker.io/v2/: Forbidden.
The proxy setting somehow is not working anymore.

The "10.245.64.1" is not working, but "91.189.89.216" works.
Looks like we just need to swap these two and this connection issue will gone.

2. The composed aarch64/ubuntu:bionic is not a valid target
I think maybe we can just fetch ubuntu:bionic directly.