[minijail] support network namespacing

Add a -e argument to minijail0 to network-namespace the target program.

BUG=None
TEST=adhoc
$ minijail0 -e `which ping` 4.2.2.1
connect: Network is unreachable
$ minijail0 `which ping` 4.2.2.1
<ordinary output...>

Change-Id: Ie58ff1ec1e1ec21987734b86cbabb1118c7e0bf0
Signed-off-by: Elly Fong-Jones <ellyjones@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/46035
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Jorge Lucangeli Obes <jorgelo@chromium.org>
3 files changed