HADOOP-16494. Add SHA-512 checksum to release artifact to comply with the release distribution policy.

This closes #1243

(cherry picked from commit 34dd9ee36674be670013d4fc3d9b8f5b36886812)
(cherry picked from commit 786df37429b984c21d0e855f969cf3ec04b1e8cb)

dev-support/bin/create-release

@@ -601,7 +601,7 @@ function signartifacts
 
   for i in ${ARTIFACTS_DIR}/*; do
     ${GPG} --use-agent --armor --output "${i}.asc" --detach-sig "${i}"
-    ${GPG} --print-mds "${i}" > "${i}.mds"
+    sha512sum --tag "${i}" > "${i}.sha512"
   done
 
   if [[ "${ASFRELEASE}" = true ]]; then