gerrit: provide option to suppress emails on some operations

When cherry picking large stacks of patches into branches, gerrit
generates emails on every operation along the way: ready, verify,
review, This results in tons of noise of which the recipients usually
do not care about.

This patch adds a command line option which allows to suppress sending
emails on ready, review, trybotready, and verify gerrit operations.

BUG=none
TEST=using the new command line option modified the 'verified' flag of
     an existing gerit patch. Observed that emails are not generated
     when --ne s passed in as a command line argument, and are
     generated in case --ne is not present.

Change-Id: I15a3ad15e4acdec294a0606a999ca7f7b3bcf5be
Signed-off-by: Vadim Bendebury <vbendeb@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/1464365
Reviewed-by: Mike Frysinger <vapier@chromium.org>
(cherry picked from commit 2e3f82da9e4dc8c0feca4c0221dc536a882d5ed8)
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/chromite/+/1500216
2 files changed