DRTVWR-418: Migrate HAVOK suppression from autobuild.xml to build.sh.

Turns out that without HAVOK, we can't build the PhysicsExtensions_TPV; but
the viewer's build.sh is unaware of CMake switches set in autobuild.xml.
Passing those CMake overrides in build.sh allows us to test that setting
elsewhere in build.sh to skip the PhysicsExtensions_TPV step -- instead of
failing the build.