EQS-494: Update tags for build-on-pr images from BRANCH_NAME to SHORT_SHA & dev-images

[VirajP1002]

Motivation and Context

The Cloud Build pipeline currently uses the raw branch name as the Docker image tag, which may include special characters like / which are not allowed in Docker tags. This is typically caused by Dependabot branch names.

What has changed

To stop builds from failing, we replace $BRANCH_NAME with $SHORT_SHA and dev-images in the cloud-build-on-pr pipeline configuration. This removes branch names from the image tag meaning that any branch with special characters won't fail any builds. Additionally, the dev-images tag will make it easier for developers to identify images alongside the commit SHA.

How to test?

1. Create a project environment following the README
2. Manually run the cir-proxy-service-build-push-on-pr pointing to this branch
3. Check your GAR for the new image and check the tags are the latest commit hash (of this branch) and dev-images

Links

Ticket