CRAS test: Verify sizes of shared structures.

This makes sure that shared structures have a fixed size across
architectures.

This test also acts as a reminder that CRAS_SERVER_STATE_VERSION
and CRAS_PROTO_VER should be bumped whenever shared structures and
message format changes.

BUG=chromium:309961
TEST=cros_workon_make --board=${BOARD} media-sound/adhd --test
     on x86 and x86_64.
CQ-DEPEND=CL:189204

Change-Id: Ie9872c8ac9cb6df531c2c821ecb554ad830d27fb