Switch to setting 'official build' for non developer builds

Some things controlled by the OFFICIAL_BUILD defined are commented as
unsafe to ship in production, so we need that as well.

Note that GOOGLE_CHROME and OFFICIAL_BUILD are two different settings,
so this just denotes the build as one shipped in production.

Change-Id: I1fdcfec7f5c5142dd2bdc5f1d1f9a296a60e5708
Reviewed-by: Michal Klocek <michal.klocek@qt.io>