Propagate tags to app-layers in docker images for all langs

[vsbus]

PR Checklist

Please check if your PR fulfills the following requirements:

• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)

PR Type

What kind of change does this PR introduce?

• Bugfix
• Feature
• Code style update (formatting, local variables)
• Refactoring (no functional changes, no api changes)
• Build related changes
• CI related changes
• Documentation content changes
• Other... Please describe:

What is the current behavior?

We are using py3_image() with layers parameter in one of our projects. These images have tags = ["manual"] so we don't expect them to build with bazel build //.... However, we observing that .tar files with layers are still built. That happened because tags were not propagated to the layer's targets. This PR is trying to fix the issue.

Issue Number: N/A

What is the new behavior?

bazel build //... doesn't build extra targets like layers when manual tag is used.

Does this PR introduce a breaking change?

• Yes
• No

Other information

[vsbus]

Hey @gravypod , please take another look

[gravypod]

Looks good. Lets just get a second review from @alexeagle since this will be a user-visible change.

[alexeagle]

thanks!