Remove art and libnativehelper from root Android.bp

art and libnativehelper have collisions between the top level directory
name and a module name, remove them from the root Android.bp file until
they have an Android.bp file to avoid a glob dependency on the directory.

Bug: 25797955
Change-Id: Ibd33df17450b171ec2390653e4cf3b00fc242831
1 file changed