GitLab

- Use the right repo for Ubuntu ARM(64)
- Add checks for valid architectures so the "All" commands work.
- Try to fix up some bashisms
- And give up on the rest and just switch to bash

BUG=632522

Review-Url: https://codereview.chromium.org/2193903004
Cr-Commit-Position: refs/heads/master@{#408861}