Use aptly base image for aptly-api container

`aptly-api` container image is built from aptly image adding command to run
aptly api service.

By using the same image both for aptly and aptly-api we can decrease number
of Drivetrain images and simplify docker image building jobs.

Prod-related: PROD-25633 (PROD:25633)

Change-Id: I16d2efba9da6331eb39cf52c3f725c932610d444
2 files changed