common: Disable multithreaded dextop on RELEASE and SNAPSHOT builds

This needs some more work before it can be considered stable enough
for use on these builds.

Change-Id: Ic80603cc59623da878875e40de92bda5caef3331
(cherry picked from commit 1df415bba20199de48e36fbe04f03c8fb9140b0e)
Update Nova Launcher to 3.02 Beta 4