This is presumably because that package exists in Java 8 and not in above, and there also aren't inherently any features providing it. I can see a few main possibilities:
Include a Jakarta EE 8 version of that API embedded in the OSGi bundle
Include an OSGi-packaged version of that alongside the main OSGi bundle
Figure out if there's an existing Liberty feature that provides this package and depend on that as well
Specifically:
Unresolved requirement: Import-Package: javax.activation.This is presumably because that package exists in Java 8 and not in above, and there also aren't inherently any features providing it. I can see a few main possibilities: