SpringBoot How to add extra operations for spring boot + buildpacks image

When using gradle + spring boot + buildpacks, how to add operations other than code to the image? The most common operation is to set the time zone for the mirror.When there is a Dockerfile file, I only need to add the RUN command to easily set the time zone. But in buildpacks, I feel very confused and don't know how to add commands

Comment From: wilkinsona

This is something that isn't as easy as we'd like at the moment. If you want to set the timezone in every image that you build, a custom builder that does so automatically without requiring any further configuration is probably your best option. Alternatively, you can use JAVA_OPTS and -Duser.timezone when running the image as described in this comment. You may also be interested in this discussion in the Paketo slack.

I'm going to close this issue in favour of #21478, #21582 and the discussion on the Paketo Slack.