Cloud API: upload stream-optimized VMDK to S3

The VMDK image must be in stream-optimized format in order to be
imported to VSphere. osbuild-composer does not produce VMDK by default
as stream-optimized. Instead, it is converted on the fly when the image
build job has been submitted via Weldr API.

Since we are aiming mainly for the VSphere use case with the VMDK image
in the service, the image should be ready for importing to VSphere.

Implement a temporary workaround for the Cloud API and AWS S3 target to
upload stream-optimized VMDK image.

Adjust the `api.sh` test case to not convert the VMDK image downloaded
form S3, before importing it to VSphere.

test/cases/api.sh

@@ -1231,12 +1231,11 @@ function verifyInVSphere() {
     _ci_iso_path="$(_createCIUserdataISO "${_ci_userdata_path}" "${_ci_metadata_path}")"
 
     VSPHERE_IMAGE_NAME="${VSPHERE_VM_NAME}.vmdk"
+    mv "${_filename}" "${WORKDIR}/${VSPHERE_IMAGE_NAME}"
 
     # import the built VMDK image to VSphere
     # import.vmdk seems to be creating the provided directory and
     # if one with this name exists, it appends "_<number>" to the name
-    greenprint "🚧 Converting the downloaded VMDK image to be streamOptimized"
-    qemu-img convert -O vmdk -o subformat=streamOptimized "${_filename}" "${WORKDIR}/${VSPHERE_IMAGE_NAME}"
     greenprint "💿 ⬆️ Importing the converted VMDK image to VSphere"
     $GOVC_CMD import.vmdk \
         -u "${GOVMOMI_USERNAME}:${GOVMOMI_PASSWORD}@${GOVMOMI_URL}" \