Change indentation style in commands definitions

Currently, the indentation level for a command's definition depends on
the command name length, and this makes the commands dict unpleasant to
the eye. This patch changes it so that a new line begins right after the
left parenthesis starting the command tuple.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Michael Hanselmann <hansmi@google.com>