.oniro-ci: assorted improvements to build pipelines

This pull request contains a number of improvements broken out of the pipeline publishing changes, so that final review is easier. Please consult individual commit messages.

.oniro-ci/build-generic.yaml

@@ -293,7 +293,7 @@
         (
           cd "$BITBAKE_TMPDIR"/deploy/
           for artifact in $CI_ONIRO_JOB_ARTIFACTS; do
-            find ./ -type f -name "$artifact" -exec cp --parents {} "$CI_PROJECT_DIR"/artifacts \;
+            find ./ -type f -name "$artifact" -exec cp --verbose --archive --parents {} "$CI_PROJECT_DIR"/artifacts \;
           done
         )
       fi
@@ -311,7+311,7 @@
 
 .build-rauc-bundle:
   extends: .build-image
   variables:
     # Put timestamp into bundle name.
     CI_ONIRO_BB_LOCAL_CONF_IMAGE_VERSION_SUFFIX: "-$${DATETIME}"
     # Collect rauc bundles as artifacts.