This variable is unknown to dpkg-buildflags. This also reduces the amount of global calls generated with GNU make 4.4 (which has a regression causing massive amounts of shell calls to be generated). Change-Id: Ia9d7099228bf5e181df4725939ed4f76f1e63dc9 (cherry picked from commitmr12.5.1bb2bf3a702) (cherry picked from commit9397dbb7ff)