On an initial upload, git-cl upload -t <title> should append <title>
before the change description.

This broke because options.squash is set to a default value very late
into code execution, so its value was not available when computing the
initial description.

options.squash is now set when parsing the options, early into code
execution.

Bug: 1064905
Change-Id: I04a18c572dd5b04a3013d39f71bc43d026ea85d3
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/2122324Reviewed-by: Josip Sokcevic <sokcevic@google.com>
Commit-Queue: Edward Lesmes <ehmaldonado@chromium.org>