Fix latest folder in releases

The gcs-upload task by default uses "gsutil cp -r" to copy the
local folder with release files to the latest folder.

That works well if "latest" does not exists, otherwise it creates
a "<version>" folder into "latest", which is not the desired
behaviour.

The "deleteExtraFiles" flag in the task means that "gsutil rsync -r"
is used instead, which achieves the correct behaviour in all
cases ("latest" exists or not.

Signed-off-by: Andrea Frittoli <andrea.frittoli@uk.ibm.com>

Author: afrittoli

tekton/release-pipeline.yaml

@@ -221,6 +221,8 @@ spec:
           value: $(params.versionTag)
         - name: serviceAccountPath
           value: $(params.serviceAccountPath)
+        - name: deleteExtraFiles
+          value: "true" # Uses rsync to copy content into latest
     - name: report-bucket
       runAfter: [publish-to-bucket]
       params: