Fix for issue #67091

Replace /dev/random to /dev/urandom to avoid generation of secret key with invalid key size.

cluster/gce/config-default.sh

@@ -217,7 +217,7 @@ resources:
     - aesgcm:
         keys:
         - name: key1
-          secret: $(dd if=/dev/urandom bs=32 count=1 2>/dev/null | base64 | tr -d '\r\n')
+          secret: $(dd if=/dev/urandom iflag=fullblock bs=32 count=1 2>/dev/null | base64 | tr -d '\r\n')
 EOM
 )
 fi