Update github-actions-metadata-update.sh

Break script if Google releases a major version update

Author: twcclegg

lib/github-actions-metadata-update.sh

@@ -40,6 +40,12 @@ GITHUB_ACTION_WORKING_DIRECTORY=$(pwd)
 echo "google/libphonenumber latest release is ${UPSTREAM_GITHUB_RELEASE_TAG}"
 echo "libphonenumber-csharp latest release is ${DEPLOYED_NUGET_TAG}"
 
+if [ "${UPSTREAM_GITHUB_RELEASE_TAG:1:1}" != "8" ]
+then
+    echo "major version update"
+    exit 123
+fi
+
 if [ "$DEPLOYED_NUGET_TAG" = "${UPSTREAM_GITHUB_RELEASE_TAG:1}" ]
 then
     echo "versions match, new release not required"