build: verifies the rpm packages signatures.

Closes #12370

scripts/build/verify_signed_packages.sh

@@ -0,0 +1,17 @@
+#!/bin/bash
+_files=$*
+
+ALL_SIGNED=0
+
+for file in $_files; do
+  rpm -K "$file" | grep "pgp.*OK" -q
+  if [[ $? != 0 ]]; then
+    ALL_SIGNED=1
+    echo $file NOT SIGNED
+  else
+    echo $file OK
+  fi
+done
+
+
+exit $ALL_SIGNED