Don't install tests by default.
Don't install tests by default.

Installing tests is a relatively rare use case, and is already
disabled by default for some qt5 modules.  Make the behavior
consistent and disable it by default here too.

Change-Id: I979053288783486f13fc2c92b87e8e3b7edfd812
Reviewed-by: Alex <3f9b327efd0f2b2e684d51660e829d1496ae5581@nokia.com>

kobolabs/qtlocation,amccarthy/qtlocation,amccarthy/qtlocation,amccarthy/qtlocation,kobolabs/qtlocation,kobolabs/qtlocation