Ubuntu 14.04, used before, has expired root SSL certificate for
Let's Encrypt. As a result, OpenSSL couldn't verify SSL certificates
issued by Let's Encrypt, failing, in particular, kernel download.
^KT-58864
Allow toolchain builder to add a suffix to toolchain name.
It is useful for rebuilding the same toolchain in different environment.
(cherry picked from commit 83148fc5bb4e8bcc5afcf119df53ec1bc854be17)