gradle: prevent the native code from being rebuilt on every build
gradle: prevent the native code from being rebuilt on every build

gradle's file copy doesn't copy the timestamp.. and can't be configured to...

GearVRf-DCO-1.0-Signed-off-by: Mihail Marinov <m.marinov@samsung.com>

xcaostagit/GearVRf,NolaDonato/GearVRf,ragner/GearVRf,rahul27/GearVRf,thomasflynn/GearVRf,rahul27/GearVRf,NolaDonato/GearVRf,xcaostagit/GearVRf,bsmr-android/GearVRf,aglne/GearVRf,NolaDonato/GearVRf,roshanch/GearVRf,rahul27/GearVRf,xcaostagit/GearVRf,NolaDonato/GearVRf,roshanch/GearVRf,bsmr-android/GearVRf,ragner/GearVRf,Samsung/GearVRf,ragner/GearVRf,roshanch/GearVRf,bsmr-android/GearVRf,aglne/GearVRf,thomasflynn/GearVRf,aglne/GearVRf,Samsung/GearVRf,xcaostagit/GearVRf,xcaostagit/GearVRf,Samsung/GearVRf,rahul27/GearVRf,NolaDonato/GearVRf,aglne/GearVRf,aglne/GearVRf,Samsung/GearVRf,Samsung/GearVRf,bsmr-android/GearVRf,thomasflynn/GearVRf,aglne/GearVRf,aglne/GearVRf,bsmr-android/GearVRf,thomasflynn/GearVRf,roshanch/GearVRf,NolaDonato/GearVRf,thomasflynn/GearVRf,NolaDonato/GearVRf,xcaostagit/GearVRf,rahul27/GearVRf,ragner/GearVRf,ragner/GearVRf,aglne/GearVRf,thomasflynn/GearVRf,rahul27/GearVRf,bsmr-android/GearVRf,Samsung/GearVRf,Samsung/GearVRf,thomasflynn/GearVRf,roshanch/GearVRf,ragner/GearVRf