Deprecate preview --create-timeout in favor of --timeout

Replace the --create-timeout option with a more generic and intuitive
--timeout option. And remove the default value to rely on the
server-side default (which is 60mins anyway).

Change-Id: Ibd8651d7a938dada6c6952607987d4ab98f24550
Merge "Deprecate preview --create-timeout in favor of --timeout"