Bug 462282 - Prevent (automatic) update to new Mac layout

This is the first part of the fix. It consists in adding a new action
that will be able to fail the installation.

Change-Id: I254612f37707b02940b4c24a2e97b98786b16d31
Signed-off-by: Pascal Rapicault <pascal@rapicorp.com>
8 files changed