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
Merge branch 'cm-11.0' of https://github.com/CyanogenMod/android_vendor_cm into cm-11.0