base: fix dialog neutral button

Some languages could do that the 3 buttons wasn't visible in screen because having
large texts. This CL gives neutral button more space to accommodate the rest
of the buttons and made space to allow all of them fit in screen

screenshots: https://cloud.ruesga.com/d/7ec51e797d/



Change-Id: I06f3b83863de5627f1294da7b661ce396ed3801c
JIRA: CML-148
Signed-off-by: Jorge Ruesga <jorge@ruesga.com>